TERMINOLOGY USED IN ANIMAL HUSBANDRY & VETERINARY SCIENCES

A

• abdomen – The middle section of the body, between the chest and the pelvis.
• abdominal cavity – The body cavity between the chest and the pelvis.
• abdominocentesis – Surgical procedure in which a needle is inserted into the abdomen to withdraw fluid.
• abortion – The end of a pregnancy before the expelled fetus can survive independently, either by spontaneous abortion (miscarriage) or by a medical termination of pregnancy.
• abscess – A pocket of pus, usually caused by a bacterial infection.
• acariasis – Disease caused by a mite of the order Acarina.
• acaricide – A chemical agent used to kill mites.
• ACE inhibitor – Any of a class of drugs intended to lower blood pressure by widening blood vessels. ACE stands for angiotensin-converting enzyme.
• acidic – A liquid that has a pH lower than 7.
• acquired – Conditions that are not inborn and that develop during the animal’s life.
• acromegaly – A disorder of excessive growth hormone secretion by the pituitary gland, resulting in excessive growth of bones in the legs.
• actinobacillosis – Disease caused by bacteria of the genus Actinobacillus.
• actinomycosis – A bacterial infection in humans, swine, and cattle that causes hard masses to form in the mouth and jaw.
• acupuncture – A procedure adapted from Chinese medical practice in which specific body areas are pierced with fine needles for therapeutic purposes.
• acute – A condition that has a brief or short course; signs often develop suddenly and may be severe.
• acute pain – The short-term sharp, throbbing, aching, or burning sensation in response to a stimulus (twisting, crushing, or burning) or tissue injury (bruises, wounds, and surgical incisions).
• Addison’s disease – A deficiency of adrenal gland hormones.
• adenocarcinoma – A malignant tumor formed in the epithelium, or covering tissue, of an organ.
• adenoma – A benign tumor formed in glandular tissue.
• adenovirus – A virus of the family Adenoviridae.
• adrenal gland – A small, paired gland located near the kidneys that produces cortisol, epinephrine, and other hormones.
• aerosol – A suspension of particles dissolved in liquid and dispersed in a fine mist.
• aflatoxicosis – Poisoning caused by consumption of foods contaminated with a toxin produced by the fungus Aspergillus flavus.
• African horse sickness – An equine viral disease that is widespread in Africa. It is characterized by signs of lung and blood system impairment, and is most frequently transmitted by midges or mosquitoes.
• agalactia – Partial or complete lack of milk flow from the mammary gland.
• agent – Anything that produces an effect. For example, viruses and bacteria are agents that cause disease.
• aggression – Behavior that is related to conflict between individuals; includes both threats and attacks.
• agonist – A drug or other chemical that can bind to a receptor or cell to trigger a response typical of a naturally occurring substance.
• agouti – A mottled coat color in rodents, characterized by fur with bands of different colors.
• airway – Passage for air from the nose or mouth to the lungs.
• algal poisoning – A toxic and often deadly condition caused by heavy growths of blue-green algae in drinking water.
• alkaline – A substance with a pH higher than 7; also referred to as basic.
• alkaloidosis – Poisoning by alkaloids, plant toxins that damage the liver.
• allergy – An abnormally high sensitivity to certain substances, such as pollens, foods, or microorganisms.
• alloimmune reaction – A type of immune reaction that occurs when the body produces antibodies against the tissues of another animal. This may occur, for example, when one animal receives a blood transfusion from another animal of the same species but with a different blood type.
• alopecia – A partial or complete loss of hair in areas where it is usually found.
• alternative therapy – Therapy used instead of conventional treatments (for example, homeopathic treatment).
• alveoli – Plural form of the word alveolus.
• alveolus – Tiny air-holding sac formed at the end of air passageways in the lungs, where the barrier between the air and the blood is a thin membrane.
• amino acid – A chemical compound that forms the basic building block of proteins.
• amoeba – A type of protozoa, or single-celled organism. Some are parasitic and can cause infection in animals.
• amphetamine – A class of drugs that stimulates the central nervous system and the cardiovascular system.
• amphibian – A class of cold-blooded animals that spends at least part of their life cycle living in water.
• amputation – The removal of a limb or other part of the body.
• amyloid – A type of abnormally folded protein that may collect in various body tissues and interfere with their function.
• amyloidosis – Disease characterized by accumulation of abnormal protein deposits.
• anabolic – Pertaining to a metabolic process in which complex molecules are created from simpler ones.
• analgesia – Treatment given to control pain; a deadening or absence of the sense of pain without loss of consciousness.
• analgesic – A class of drugs that relieve pain.
• anaphylactic shock – A rare, life-threatening, immediate allergic reaction to something that has entered the body, such as food, an injection, or an insect sting. Also called anaphylaxis.
• anemia – An abnormally low red blood cell count caused by insufficient intake of iron in the diet, blood loss, or other medical conditions.
• anesthesia – A lack of all sensation, particularly sensitivity to pain. It can be induced medically or result from trauma, and it can be limited to a small area (local anesthesia) or affect the entire body (general anesthesia).
• anesthetic – An agent used to induce anesthesia, including injectable drugs and inhaled gases.
• anestrus – An interval of sexual inactivity between 2 periods of estrus in female mammals that breed cyclically.
• aneurysm – A dilation or bulging of a blood vessel caused by a weakening of its walls.
• animal-assisted therapy – Using animals as therapy for the sick or elderly in nursing or other rehabilitation centers because of the positive effect such visits have on residents and patients.
• animal welfare – Human efforts to reduce and prevent pain and suffering and promote well-being in animals.
• anorexia – A lack or loss of appetite.
• anoxia – Lack of oxygen in the blood or body tissues.
• antacid – A medication that neutralizes acidity, especially in the stomach.
• antagonist – A drug or substance that nullifies the effect of another substance.
• anterior – Located toward the head or the front end of the body.
• anterior uvea – Part of the front portion of the eye, including the iris and ciliary body.
• anthelmintic – A class of drugs used to treat infection with parasitic worms.
• anthrax – An often-fatal infectious disease caused by Bacillus anthracisbacteria that may infect all warm-blooded animals, including humans.
• antibacterial – Destroying or inhibiting the growth of bacteria.
• antibiotic – A class of drugs used to destroy bacteria while remaining safe for the human or animal being treated.
• antibiotic resistance – Ability of a microorganism (such as bacteria) to resist the effects of an antibiotic drug.
• antibody – A molecule produced by the immune system that attacks a particular foreign substance (antigen) in the body.
• anticholinergic – A class of drugs that block acetylcholine receptors in nerves.
• anticoagulant – A substance that stops blood from clotting.
• anticonvulsant – A class of drugs used to prevent or relieve convulsions.
• antidepressant – A class of drugs designed to relieve depression in humans; may also be used to help control behavior problems in pets.
• antidote – A substance that counteracts the effect of a poison or toxin.
• antiemetic – One of a group of drugs used to retard or stop vomiting.
• antifungal – A class of drugs that destroy or prevent the growth of fungi.
• antigen – Any substance that can stimulate an immune response.
• antihistamine – A class of drugs used to relieve allergy signs by blocking the inflammatory action of histamines.
• anti-inflammatory – Medication that prevents or reduces inflammation.
• antimicrobial – A large group of drugs used to fight infections caused by bacteria, fungi, and viruses.
• antineoplastic – A group of chemical agents or drugs used to combat cancer.
• antioxidant – A substance that inhibits oxidation of other compounds.
• antiparasitic – Any of a group of drugs used to combat infestation with parasites.
• antiseptic solution – A solution of a substance that kills or inhibits the growth of microbes.
• antitoxin – A compound that neutralizes a specific toxin.
• antivenin – An antidote to a particular venom; a serum that counteracts venom.
• antiviral – Compound that kills or inhibits the growth of viruses.
• anus – The opening at the end of the intestinal tract where solid wastes are pushed out of a body.
• aorta – The largest artery in the body. It carries blood away from the heart on its way to distribute oxygen to all body tissues except the lungs.
• aortic arch – The curved portion between the ascending and descending portions of the aorta.
• aortic valve – A heart valve comprising 3 flaps that controls the flow of blood from the left ventricle into the aorta.
• aplasia – Incomplete or incorrect development of a body part.
• aquatic – Describes organisms that live in water.
• arboreal – Describes species that spend most or all of their lives in trees.
• arrhythmia – An abnormal pattern of contraction of the heart, caused by a disturbance in conduction of the normal electrical impulses within the heart.
• arsenical – A substance (a drug or insecticide) containing arsenic.
• arterial dilator – A drug that dilates the small arteries, making it easier for the heart to pump blood away from itself.
• artery – Blood vessel that carries oxygen-rich blood away from the heart and toward the body’s tissues.
• arthritis – Inflammation of a joint; often characterized by swelling, pain, and redness.
• arthroscopy – Examination of the interior of a joint, such as the knee, using a type of endoscope that is inserted into the joint through a small incision.
• artificial insemination – Introduction (with a syringe or other device) of semen into the uterus without sexual contact.
• ascarid – A class of roundworms whose larvae can cause disease.
• ascites – A condition in which fluid collects in the abdomen.
• as-needed dosing – Administering pain medication only when the animal shows recognizable signs of pain.
• aspergillosis – A fungal infection caused by several species of Aspergillus
• asphyxiation – A severe lack of oxygen resulting from inability to breathe.
• aspiration – The use of a suction device to withdraw fluid from the body.
• aspiration pneumonia – Inflammation caused by inhalation of food particles or fluids into the lungs.
• asthma – A respiratory condition marked by recurring episodes of labored breathing, wheezing, and coughing, triggered by oversensitivity to environmental conditions.
• astringent – A substance that causes tissues, such as mucous membranes, to shrink or dry out.
• atherosclerosis – A hardening of an artery caused by deposits made of cholesterol, other fatty substances, or cellular debris that accumulates inside the artery.
• atopy – Allergy characterized by itching and redness of the skin; may also include discharges from the eyes or nose.
• atria – Plural form of the word atrium.
• atrial fibrillation – Irregular contraction of the atria (upper heart chambers) caused by abnormal electrical activity in the heart.
• atrial standstill – A failure of the electrical impulses in the upper chambers of the heart, which results in a lack of contraction of those chambers.
• atrial thrombosis – A heart condition caused by a blood clot in the atrium of the heart.
• atrioventricular valve – The valve between the upper (atrial) and lower (ventricular) chambers of the heart.
• atrium – The upper chamber of the heart that receives blood from the veins and pushes it into the ventricle.
• aural plaque – In horses, a white growth caused by a virus that develops in and around the ears.
• autoimmune – An immune response that is developed against the animal’s own tissues.
• autonomic nervous system – Specialized set of neurons controlling and regulating basic, unconscious bodily functions such as breathing and heart beat.
• avian tuberculosis – A slowly spreading, chronic infection of birds caused by the bacteria Mycobacterium aviumand characterized by gradual weight loss.
• awn – A slender, bristle-like appendage found on the spikelets of many grasses.
• axon – Extensions of neurons that transmit electrical charges away from the cell body.

B

• B cell – A type of white blood cell that produces antibodies.
• bacteremia – The presence of bacteria in the bloodstream.
• bacteria – The plural form of the word bacterium.
• bacterial disease – Disease caused by invading bacteria or an overgrowth of usually harmless bacteria.
• bacterium – A microscopic, single-celled organism that may cause disease or may be a harmless, or even helpful, part of an animal’s normal internal or external environment.
• barbering – Excessive chewing of hair or feathers that leads to bald patches of skin.
• baroreceptors – Nerve endings in blood vessels that are sensitive to blood pressure changes.
• basal cells – Cells at the base of the top layer of the skin.
• basking – The behavior of a cold-blooded animal lying in the sun to increase its body temperature.
• basophil – A type of white blood cell that releases histamine as part of the body’s allergic response.
• benign – Something that is nonharmful or noncancerous.
• besnoitiosis – Infectious disease caused by protozoa of the genus Besnoitia, transmitted by certain biting flies and ticks, found in Africa, France, and Mexico.
• beta cells – Cells in the pancreas that produce insulin.
• biceps brachii tendon – Tendon of the biceps brachii, a major muscle of the upper front leg that acts to bend the elbow joint.
• biopsy – The removal of a small sample of tissue or fluid for examination. A sample is obtained in a way suited to the type of tissue and its location; it might be drawn out with a hollow needle and syringe, scraped with a curette, or cut away with a scalpel.
• bladder – A stretchable, membranous sac-like structure in the body that holds fluids; the term is used most often to refer to the urinary bladder.
• blastoma – A tumor composed of previously healthy young cells that never mature normally, but mutate into a cancer.
• blastomycosis – A disease caused by Blastomycesfungi that can affect several species of animals or humans; infection may occur in the skin, lungs, or other body organs.
• blepharitis – Inflammation of the eyelids.
• blind spot – The small circular area, insensitive to light, where the optic nerve enters the eye. See alsooptic disk.
• blister – A fluid-filled bump on the skin.
• blood cell count – The number of red blood cells, white blood cells, and platelets in a sample of blood. Also called a complete blood count (CBC).
• blood cells – Any of the cells contained in blood. See alsoerythrocyte, leukoctye, platelet.
• blood clot – A mass of blood cells, protein, and platelets, also known as a thrombus, that forms whenever there is a break or tear in a blood vessel.
• blood poisoning – A disorder, also known as septicemia, in which bacteria or their toxins circulate in the bloodstream.
• blood pressure – The force exerted by the blood against the walls of the blood vessels, especially the arteries.
• blood transfusion – A procedure in which another animal’s blood is introduced into the body to counteract blood loss, anemia, or other conditions.
• blood typing – The identification of blood groups in order to match donor blood with the recipient’s blood for a blood transfusion.
• bloodborne – Carried by or transmitted through blood.
• bloodstream – The flow of blood through the circulatory system of an organism.
• body cavity – An enclosed space in the body that contains organs, such as the cranial, spinal, thoracic, and abdominal cavities.
• boid snakes – Snakes related to boa constrictors. The group includes pythons.
• bone marrow – A soft tissue filling the spaces of the spongy tissue found at the ends of long bones. It produces red blood cells, most types of white blood cells, and platelets.
• borreliosis – Disease caused by bacteria of the genus Borrelia. SeeLyme disease.
• botulism – Infection caused by ingesting food or dead flesh containing toxins produced by the bacterium Clostridium botulinum, or by absorbing toxins in the gastrointestinal tract. It results in rapid paralysis and death.
• brachycephalic – Short-headed or broad-headed.
• brachygnathia – Abnormal shortness or recession of the lower jaw.
• brachytherapy – A cancer treatment that involves internal radiation therapy.
• brackish – Water that is a mixture of fresh and salt water.
• bradycardia – A slower than normal heart rate.
• brain – The controlling center of the nervous system in vertebrates, connected to the spinal cord and enclosed in the cranium.
• brain stem – One of the 3 main sections of the brain; it controls many basic life functions.
• brain stem auditory evoked response (BAER) – Records electrical activity in the pathway from the sound receptors in the ear to the brain stem and cerebrum.
• breed – A group of animals or organisms having common ancestors and certain distinguishable characteristics.
• breeding – Sexual reproduction of animals, either spontaneously or planned and supervised by human beings.
• broad-spectrum antibiotics – Antibiotics that are effective against a wide range of bacteria.
• bronchial – Relating to the bronchi, the bronchial tubes, or the bronchioles, the body’s airways.
• bronchitis – Inflammation of the bronchial airways.
• bronchoscopy – Interior examination of the airways with an endoscope.
• buck – The male of certain mammal species, such as rabbits, antelope, and deer.
• budgerigar – A small Australian parrot commonly kept as a pet; also called a budgie or parakeet.
• bumblefoot – A foot abscess in sheep, guinea pigs, or birds caused by a localized bacterial infection.
• bursa – A fluid-filled body sac located between a tendon and a bone or at points of friction.

C

• calcification – The abnormal hardening or stiffening of a body part caused by deposits of calcium.
• calcinosis – The abnormal depositing of calcium salts contributing to hardening of a part or tissue of the body.
• calcinosis cutis – A condition in which calcium deposits form in the skin; they can appear as small, thickened, “dots” on the abdomen.
• calcitonin – Hormone secreted by the parathyroid glands that regulates levels of calcium in the bloodstream.
• calcium deficiency – A lack of calcium in the body that can result from insufficient calcium or vitamin D in the diet and can cause bone deformities.
• caloric – Relating to heat or calories.
• cancer – A malignant tumor or growth that destroys healthy tissue.
• cancer pain – Pain resulting from primary tumor growth, a spreading cancerous disease, or the toxic effects of chemotherapy or radiation.
• candidiasis – A fungal disease caused by Candida albicansthat affects the mucous membranes and the skin.
• Canidae – Scientific name for dogs, foxes, and wolves.
• canine – Relating to animals of the Canidae family, primarily dogs.
• canine distemper (hardpad disease) – A highly contagious, usually fatal viral disease of dogs, ferrets, mink, raccoons, and other mammals.
• canine herpesviral infection – A severe, often fatal, viral disease of puppies, sometimes referred to as fading or sudden-death syndrome. In adult dogs, it may be associated with upper respiratory infection or an inflammation of the vagina marked by pain and a pus-filled discharge (in females) or inflammation of the foreskin of the penis (in males).
• canine thrombopathia – A hereditary disorder of blood platelets that causes bleeding from the nose and gums, and tiny purple or red bruises as a result of bleeding under the skin.
• canine tooth – Long, pointed tooth used primarily for holding food in place in order to tear it.
• cannibalism – The act of eating a member of an animal’s own species.
• capillary – The smallest type of blood vessel, which connects small blood vessels that branch off from arteries and veins.
• capsule – A medication consisting of an active ingredient and fillers, enclosed in a cylindrical coating usually made of gelatin; designed to be taken by mouth.
• carcass – The dead body of an animal.
• carcinogen – A cancer-causing substance or agent.
• carcinoma – An invasive, malignant tumor derived from epithelial tissues (tissues that make up the skin, glands, mucous membranes, and organ linings).
• cardiac – Of or relating to the heart.
• cardiac output – The amount of blood pumped from the heart during a specified period of time.
• cardiac shunts – Abnormal openings between chambers of the left and right sides of the heart.
• cardiac tamponade – A buildup of fluid in the sac around the heart, which increases pressure on the heart and gradually interferes with its ability to pump blood.
• cardiomyopathy – A disease in which the heart muscle is weakened.
• cardiopulmonary resuscitation (CPR) – An emergency procedure, often employed after cardiac arrest, in which massage of the heart, artificial respiration, and drugs are used to maintain the circulation of oxygenated blood to the body. Also called cardiopulmonary-cerebral resuscitation (CPCR).
• cardiovascular system – The body system that consists of the heart and the blood vessels (veins and arteries).
• carnivore – A flesh-eating animal.
• carpal – Relating to bones in the wrist; a wrist bone.
• carpal joint – Any of the joints between the carpal bones.
• carrier – An animal that, without becoming ill, harbors or spreads disease-causing microorganisms.
• cartilage – A somewhat elastic connective tissue that is found at the ends of bones and helps reduce friction as joints move.
• castration – Most often refers to surgical removal of the testicles; less commonly may refer to removal of the ovaries.
• cataract – Condition in which the lens of the eye progressively loses transparency, which often results in loss of vision.
• cathartic – A drug given to increase the passage of gastrointestinal contents, to cleanse the bowel before radiography or endoscopy, to eliminate toxins from the gastrointestinal tract, and to soften feces after intestinal or anal surgery.
• catheter – A thin flexible tube that is inserted into a body cavity, duct, or vessel to allow passage of fluids.
• cationic – A substance or class of detergents that are locally corrosive, causing skin, eye, and mucous membrane injury similar to that of alkaline corrosive agents.
• ceiling effect – Situation in which an increased dose of a pain-relieving drug provides incrementally smaller gains in pain relief.
• cell – The smallest functioning unit in the structure of an organism.
• cell body – The center portion of a neuron.
• cellular infiltrates – Gas, fluid, or dissolved matter that enters cells or tissue.
• centesis – Procedure in which a needle is inserted into a structure (for example, the chest or urinary bladder) of an animal to remove fluid or air.
• central nervous system – The part of the nervous system that includes the brain and spinal cord.
• cercariae – Parasitic larvae of trematode worms.
• cerebellar hypoplasia – Lack of development of the cerebellum, the section of the brain that controls motor function.
• cerebellum – The cauliflower-shaped brain structure located just behind the cerebrum and above the brain stem.
• cerebrospinal fluid – The fluid surrounding the brain and spinal cord.
• cerebrum – One of 3 main sections of the brain; area where sensory and motor nerve activity is coordinated.
• cesarean section – A surgical procedure in which the abdomen and uterus are cut open and the young are delivered through the abdomen.
• cestode – Intestinal parasitic worm of the class Cestoda, with a flat, segmented body; tapeworms.
• chelonians – Tortoises and turtles.
• chemotherapy – The use of chemical agents to treat diseases, especially cancer.
• cherry eye – Swelling and inflammation of the third eyelid, especially in dogs.
• chlamydiosis – Infection with a bacteria of the genus Chlamydia.
• Chlamydophila – Bacteria that cause serious respiratory infections in birds.
• cholesteatomas – Cysts on the eardrum that may extend into the middle ear.
• chondrosarcoma – A malignant tumor of cartilage.
• chordae tendineae – Strands of connective tissue in the heart that connect the valves to the papillary muscles of the heart’s ventricles.
• choroid – A membrane between the retina and sclera of the eye.
• chromosome – Dense strands of material in the cell nucleus that carry the individual’s genetic material (DNA).
• chronic – A condition that persists over a long period of time, often months or longer.
• chronic pain – Pain that persists for longer than the expected time frame for healing, or pain associated with progressive, noncancerous disease, such as osteoarthritis.
• cilia – Tiny, hairlike projections that line the outer part of cells in some tissues, including the lower respiratory tract.
• cilia-associated respiratory Bacillus – Bacteria that can cause chronic respiratory disease in rats and mice; transmitted by direct contact.
• ciliary muscles – The muscles in the eye that change the shape of the lens in order to keep vision in focus.
• cleft palate – A congenital abnormality that creates a gap along the center of the roof of the mouth.
• cloaca – In amphibians, fish, birds, and reptiles, an opening through which the digestive, urinary, and reproductive tracts exit the body.
• cloacal prolapse – A condition in which the cloaca protrudes outside the body.
• cloacitis – Inflammation of an animal’s cloaca. See
• clostridia – Bacteria that can cause severe intestinal disease or spread toxins through the bloodstream.
• clot – A collection of red blood cells, white cells, and platelets, bound together by protein fibers, that plugs holes in blood vessels.
• coagulation – The process by which liquid blood is transformed into a clot.
• cobalt therapy – A type of radiation therapy that uses radioactive cobalt to treat cancer.
• Coccidia – A group of protozoan parasites (small, single-celled organisms) that infect the intestinal tract of animals.
• coccidioidomycosis – A dustborne, noncontagious infection caused by inhalation of fungal spores.
• coccidiosis – A serious disease in cattle, sheep, goats, hogs, poultry, and rabbits, and less serious in dogs, cats, and horses. It is caused by protozoans (Coccidia) that invade and may destroy the lining of the intestines.
• cochlea – A snail-shaped cavity in the inner ear, containing the organs of hearing.
• coelomitis – Inflammation of the coelom, or abdomen, in retiles.
• cognitive dysfunction – Senility; similar to Alzheimer’s disease in people.
• cold-blooded – Animals that do not maintain a constant internal body temperature; instead, their temperature is greatly influenced by their environment.
• colibacillosis – A form of diarrhea caused by Escherichia coli
• colic – Severe abdominal pain caused by spasm, obstruction, or distention of the intestines; there are many possible causes.
• colitis – Inflammation of the colon.
• collagen – A fibrous protein that forms tendons, ligaments, and connective tissue; also found in skin, bone, and cartilage.
• colon – The large intestine.
• colonoscopy – Examination of the inside surface of the colon using a tube inserted through the rectum.
• colony – A group of organisms of one species that live and interact closely with each other in an organized fashion.
• colostrum – The watery fluid rich in antibodies and nutrients that is produced by a mother after giving birth and before producing true milk.
• colt – A young male horse.
• combination chemotherapy – Using a combination of drugs that target different sites or that employ different mechanisms to maximize destruction of cancer cells.
• companion animal – Any animal kept by humans for companionship or pleasure rather than for utility; a pet.
• compensatory mechanism – Any one of several specific responses the body uses in combating heart disease to maintain normal circulation.
• complementary therapy – Therapy used in addition to conventional treatments.
• compulsive behavior – Otherwise normal behaviors that occur out of context or so often that they interfere with normal activity.
• computed tomography (CT) – A computer-enhanced x-ray procedure used to detect abnormalities in various body organs.
• conduction – Passage of the electrical impulses that govern the pumping of the heart.
• conformation – The structure or outline of an item or entity, determined by the arrangement of its parts.
• congenital defect – An abnormality that is present at birth, as a result of either heredity or environmental influence such as a toxin or infection.
• congestion – An abnormal buildup of fluid in an organ or area of the body.
• congestive heart failure – A condition marked by weakness, shortness of breath, or an excessive buildup of fluid in the tissues or body cavities when the heart fails to maintain adequate blood circulation.
• conjunctiva – The mucous membrane lining the inside of the eyelids.
• conjunctivitis – Inflammation of the mucous membrane lining the inside of the eyelid. Also called pink eye.
• constipation – Difficulty in passing bowel movements; incomplete or infrequent passing of hard stools.
• constricted toe syndrome – A condition in newly hatched birds in which a tough ring of tissue forms around a toe joint, partially cutting off circulation.
• contagious – Describes a condition that can spread from one organism to another.
• contaminated – Unclean or polluted because of contact with harmful substances.
• contraction – Pumping action of the heart muscle or other muscles.
• contrast procedure – Specialized x-ray technique in which the animal is given a dye that shows up on the x-ray film to help provide more detailed images of body organs.
• convulsion – See
• coprophagia – Eating feces.
• cornea – The transparent outer part of the eye that covers the iris and pupil and admits light into the eyeball.
• coronavirus – A family of viruses that chiefly cause respiratory infections.
• corticosteroid – Any of the steroid hormones made by the adrenal gland or their synthetic equivalents; commonly used to reduce inflammation.
• cortisol – A steroid hormone produced by the adrenal gland that regulates carbohydrate metabolism and maintains blood pressure.
• counterconditioning – A method for reducing unwanted behavior by teaching a pet to replace it with a more favorable behavior.
• counterirritant – A substance that, when applied, irritates the skin and thereby reduces the inflammation of underlying tissue.
• counterpressure – Pressure applied to reduce bleeding.
• cranial – Relating to the skull, or cranium; toward the head end of the body.
• cranium – The portion of the skull enclosing the brain.
• cream – A semisolid mixture made for application to the skin or mucous membranes.
• crop – In many birds, a pouch in the gullet where food is stored and sometimes partially digested before passing to the stomach.
• cross matching – Blood typing test done to ensure that a blood donor and recipient have compatible blood types.
• crotalids – Snakes of the genus Crotalidae, including pit vipers (rattlesnakes, for example).
• cryptococcosis – A fungal disease that may affect the respiratory tract (especially the nasal cavity), central nervous system, eyes, and skin (particularly of the face and neck of cats).
• cryptorchidism – A developmental defect marked by the failure of one or both testes to descend into the scrotum.
• cryptosporidiosis – Intestinal infection with Cryptosporidiumparasites, the primary sign of which is diarrhea.
• Cryptosporidium – A genus of single-celled protozoal parasites that causes intestinal infection in several species, including humans.
• CT scan – Seecomputed tomography.
• culture – A method of encouraging a microorganism to grow in a laboratory in order to identify specific bacteria or viruses that may be present.
• Cushing’s disease – A hormonal disease characterized by overproduction of cortisol from the adrenal gland; most often caused by a tumor of the pituitary gland in the brain.
• cutaneous – Of or relating to the skin.
• cyst – A closed, fluid-filled growth in otherwise normal tissue.
• cystitis – Inflammation of the bladder.
• cystocentesis – Extraction of a sample of urine directly from the bladder using a needle and syringe.
• cytokine – A protein secreted by cells of the immune system that helps regulate inflammatory responses.
• cytology – The study of the structure and function of individual cells.
• cytotoxic – Substance that is poisonous to cells.

D

• debilitated – Having greatly decreased energy and strength.
• debulking – A surgery done to remove part of a cancer or tumor.
• decongestant – A medication that reduces mucosal congestion.
• defecate – To expel feces from the intestinal tract.
• defibrillation – A process of shocking the heart in a specific way to restore a coordinated heart beat and a pulse.
• deficiency – A lack of something that is required for normal body function.
• degeneration – A condition that causes a gradual deterioration in the structure or function of a body part.
• degenerative joint disease – A form of arthritis characterized by gradual loss of cartilage of the joints. Also called osteoarthritis.
• dehydration – A lack of sufficient water within the body.
• dendrite – Extension of a neuron that receives signals from other neurons and transmits electrical charges to the cell body.
• dental abscess – An infected cavity in a tooth, soft tissue surrounding the teeth, or bone of the jaw.
• dental malocclusion – A misalignment of the teeth in which the upper and lower surfaces fail to come together properly.
• depression – In animals, this usually refers to lowered activity and lack of interest in surroundings.
• dermatitis – Inflammation of the skin.
• dermatologist – A specialist in the treatment of skin disorders.
• dermatophytosis – A fungal infection of the skin. Also known as ringworm.
• dermis – The middle layer of the 3 layers of the skin.
• descending aorta – The part of the aorta that passes through the chest and into the abdomen, supplying blood to the trunk and rear legs.
• desensitization – A way to gradually teach a pet to tolerate a situation by carefully exposing it to that situation in small steps.
• detergent – A cleansing substance, especially a liquid soap.
• dewlap – Loose skin on the underside of an animal’s neck; this is normal in many species.
• diabetes insipidus – A metabolic disorder caused by a lack of antidiuretic hormone, which leads to production of large amounts of dilute urine and excessive thirst.
• diabetes mellitus – A metabolic disorder characterized by a deficiency in the hormone insulin and an accompanying inability to properly digest sugars; signs include excessive urination, too much sugar in the blood, thirst, hunger, and weight loss.
• diagnosis – The identification of a disease based on its signs, physical examination, and appropriate tests.
• diaphragm – A thin muscle that separates the abdominal and thoracic cavities and expands the chest during respiration.
• diarrhea – The abnormally frequent discharge of soft or liquid feces.
• diastole – The first half of a heartbeat, during which the upper chambers of the heart (atria) contract and send blood into the lower chambers (ventricles).
• diestrus – A short period of sexual inactivity between 2 estrus periods, during which the uterus is prepared for a fertilized egg.
• dietary indiscretion – Unhealthy eating, as of trash, large amounts of table scraps, or other inappropriate food.
• digestion – The process by which an animal processes food and absorbs nutrients.
• digestive tract – The system of organs responsible for digestion.
• dilate – To widen or enlarge.
• dilated cardiomyopathy – A heart disease in which the heart is enlarged and the heart muscle is weakened.
• direct life cycle – A pattern in which a parasite needs only 1 host in which to grow, breed, and reproduce itself.
• discharge – Any fluid that emerges from a sore or infection.
• disinfectant – A chemical used to kill germs.
• dislocation – Displacement of a body part, especially of a bone, from its usual fitting in a joint.
• displacement activity – The resolution of a behavior conflict by performing a seemingly unrelated activity such as grooming or sleeping.
• disseminated intravascular coagulation – A condition in which small blood clots develop throughout the bloodstream, blocking small blood vessels and destroying the platelets and clotting factors needed to control bleeding.
• dissemination – The spread of a disease-causing organism throughout the body, causing signs in multiple parts of the body.
• distemper – An airborne viral disease of dogs and some related animals such as raccoons; signs include fever, vomiting, diarrhea, loss of appetite, dehydration, tremors, weakness, and incoordination.
• distended – Swollen or expanded, as by pressure from within; dilated.
• distillation – The evaporation and subsequent collection of a liquid by condensation as a means of purification.
• diuretic – A medicine usually prescribed to reduce fluid overload; increases urine production.
• DNA – Deoxyribonucleic acid; the molecule that encodes genetic information in the nucleus of cells and is capable of self-replication.
• doe – A female of any of several species, including rabbits and deer.
• dormant – Existing in a temporarily inactive form or state, or biological rest.
• duodenum – The first and smallest portion of the small intestine, beginning at the stomach.
• dustborne – Carried by exterior or interior dusts, often used to describe bacteria transmitted in this way.
• dysecdysis – Improper or incomplete shedding of the skin in reptiles.
• dysplasia – Abnormal growth, development, or placement of body parts.
• dystocia – Abnormal or difficult birth.
• dystrophy – A degenerative condition caused by a nutritional defect or disorder.

E

• ear canal – The tube connecting the external ear with the eardrum.
• ear mites – Tiny organisms resembling ticks that can infect the ear canal of animals, especially dogs and cats.
• eardrum – The membrane at the end of the ear canal that transmits sound waves to the middle ear.
• ecdysis – The act of molting, or shedding, an outer skin layer.
• echocardiography – A type of ultrasonography used to examine the heart.
• eclampsia – A condition marked by a sudden drop in blood calcium levels, caused by the production of milk after giving birth; often leads to convulsions and coma.
• ecosystem – A community of interdependent living organisms and the environment they inhabit.
• ectoparasite – A parasite that lives on its host’s skin, hair, or feathers, such as fleas and ticks.
• ectotherm – An animal that cannot regulate its own body temperature and is instead dependent on the temperature of its surroundings (for example, reptiles and amphibians); commonly referred to as cold‑blooded.
• ectropion – A slack eyelid edge that is turned outward.
• edema – The abnormal accumulation of fluid in a tissue.
• egg binding – A condition in birds and reptiles in which the female is unable to lay a developed or partially developed egg.
• ehrlichiosis – A tickborne bacterial infection that affects white blood cells.
• elapid – A member of a family of venomous snakes with hollow fangs, such as cobras.
• electrocardiogram (EKG) – A recording of the heart’s electrical activity made by attaching a set of electrodes to the skin.
• electrocardiography – Recording of the electrical activity of the heart.
• electrolytes – Ions, or salts, such as sodium and potassium, that are present in blood and other bodily fluids and help regulate various metabolic processes.
• electromyography – An electrical recording of muscle activity that aids in the diagnosis of diseases affecting muscles and peripheral nerves.
• ELISA – An abbreviation for enzyme-linked immunosorbent assay, a test used to detect a disease-causing agent such as a virus.
• Elokomin fluke fever – An infectious disease of dogs acquired by eating raw fish infected with flukes that carry the disease-causing bacteria.
• emaciation – A condition in which the animal is abnormally thin, generally as the result of malnutrition or disease.
• embolism – Obstruction of a blood vessel by a blood clot that breaks off from its point of origin and lodges elsewhere.
• embolus – Portion of a blood clot that breaks free and travels through the cardiovascular system.
• embryo – The earliest stage of development of an animal in the womb, before any of the major body organs have formed.
• emphysema – Abnormal accumulation of air in tissues; often affects the lungs and causes breathing difficulties.
• emulsifier – A chemical agent used to bind together substances that normally do not bind.
• emulsion – A suspension of one liquid in another with which the first will not mix (for example, oil and water).
• encephalitis – Inflammation of the brain; often caused by an infection.
• encephalitozoonosis – A protozoal infection of rabbits and occasionally of mice, guinea pigs, rats, and dogs that affects multiple organs; also called nosematosis.
• encysted – Enclosed in a cyst, sac, bladder, or vesicle (for example, an encystedtumor).
• endocarditis – Inflammation of the membranes lining the heart cavity.
• endocrine – Related to glands that deliver hormones into the bloodstream.
• endoparasite – A parasite that lives inside its host, such as a heartworm.
• endoscope – An instrument for examining visually the interior of a bodily canal or a hollow organ such as the colon, bladder, or stomach.
• endoscopic gastric biopsy – A sample of stomach tissue taken with an endoscope, a long, flexible tube equipped with a camera and other instruments that is inserted through the mouth into the stomach.
• endoscopy – A procedure in which a tube called an endoscope is inserted into a hollow organ. The tube generally has a camera for maneuvering and frequently has tools such as forceps or scissors attached.
• endotoxin – A substance found in the cell walls of some bacteria that causes toxic shock, fever, and inflammation in mammals.
• endotracheal tube – Tube inserted into the trachea to deliver oxygen or anesthetic gas.
• engorge – To fill with blood.
• enterolith – A hard mass composed of magnesium ammonium phosphate crystals that forms around a foreign object (such as a stone or nail) in the large intestine, most commonly in horses.
• enterotoxemia – The presence of bacterial toxins in the bloodstream.
• entropion – A turned-in edge of the eyelid, which leads to irritation of the eyeball from the eyelashes.
• enzootic – A disease that is continually present in a particular location.
• enzyme – A protein that speeds up a biological process such as digestion.
• eosinopenia – A decrease in the number of eosinophils (a type of white blood cell) in the bloodstream.
• eosinophil – A type of white blood cell that plays a role in the immune response by ingesting bacteria and other foreign cells, immobilizing and killing parasites, and participating in allergic reactions.
• eosinophilia – An increase in the number of eosinophils (a type of white blood cell) in the bloodstream.
• epidemic – An outbreak of a contagious disease that spreads rapidly and widely.
• epidermis – The outer layer of the 3 layers of the skin.
• epidural anesthesia – Injection of pain-relieving or numbing drugs into the space surrounding the spinal cord to decrease sensation in parts of the body below that portion of the spinal cord; often used to provide anesthesia for surgery.
• epilepsy – An inherited disease that causes seizures; generally requires treatment with anticonvulsants.
• epithelial – Having to do with the skin (epithelium).
• epizootic lymphangitis – A fungal disease that affects the skin, lymph vessels, and lymph nodes of the limbs and neck of horses.
• equine – Related to or having to do with horses.
• equine granulocytic ehrlichiosis – An infectious disease of horses caused by a bacterium found in the bloodstream and transmitted by ticks.
• equine infectious anemia – An incurable, viral bloodborne infection of horses transmitted by blood-sucking insects.
• equine morbillivirus pneumonia – A short-term, often fatal, viral respiratory infection of horses caused by the Hendra virus.
• equine protozoal myeloencephalitis – Protozoal infection of the nervous system of horses.
• equine sarcoid – See
• equine viral arteritis – A short-term, contagious, viral disease of the horse family that affects multiple body systems.
• erosion – A shallow or superficial ulcer or sore, typically on the skin.
• erythrocyte – A red blood cell.
• erythropoiesis – The formation and production of red blood cells.
• erythropoietin – A hormone secreted by the kidneys that triggers the production of red blood cells in bone marrow.
• esophagus – The muscular tube that connects the throat to the stomach.
• estrous – Of, relating to, or being in heat (estrus).
• estrous cycle – The recurring physiological and behavioral changes that take place from one period of estrus (heat) to another.
• estrus – A recurring period of increased sexual desire during which a female mammal will allow sexual activity and is capable of conceiving.
• euthanasia – The deliberate, painless killing of an incurably ill or injured animal; also called putting to sleep or putting down.
• excretion – The process for removing waste matter from the blood, tissues, or organs.
• exertional rhabdomyolysis – A metabolic disorder caused by intense exercise in which toxins from muscle injury can damage other tissues, especially the kidneys.
• exoskeleton – A skeletal structure outside the body, as in insects.
• exotic pets – Nontraditional pets; animals that are not domesticated.
• expectorant – A medicine that thins airway secretions, making them easier for the animal to cough up.
• exposure – Contact with or proximity to some environmental condition, toxin, or infectious agent.
• eyelid atresia – A congenital condition in which the eye opening is reduced or closed entirely over otherwise normal eyes.

F

• failing heart – Any heart with a reduced ability to contract.
• farcy – A contagious, incurable bacterial infection of horses that may affect the skin or lungs. Also called glanders.
• farrier – A person who makes and fits horseshoes.
• fasting – Withholding food from an animal for a certain length of time.
• fatal – Causing or capable of causing death.
• fatty acid – One of the major components of fat, used by the body to supply energy and build tissues.
• fecal – Relating to or consisting of feces.
• feces – The solid waste from an animal.
• feed hopper – A simple device that uses gravity to keep a trough or bowl filled with food as animals eat.
• feline – Of or having to do with cats.
• feline distemper – Seefeline panleukopenia.
• feline infectious enteritis – Seefeline panleukopenia.
• feline infectious peritonitis – A progressive viral infection of cats that affects multiple body systems and causes a variety of signs.
• feline leukemia virus – A cancer-causing virus of cats that infects cells of the immune system and frequently results in death.
• feline lymphoma – A tumor of the immune system that is the most frequently diagnosed cancer of cats.
• feline panleukopenia – A viral infection of cats that affects multiple body systems; most infections cause no signs, but if signs are present the infection is serious and usually fatal.
• femur – The large bone of the upper hind limb; also known as the thigh bone.
• fertility – The ability to produce offspring.
• fertilization – The combination of a sperm cell and an egg cell into a developing organism.
• fetal – Having to do with a fetus or its development.
• fetal membranes – The thin layers of tissue that surround the embryo during its development. Also called amniotic sac.
• fetus – A developing animal from the stage at which the major organs form until birth. See also
• fever – Abnormally high body temperature.
• fibrocartilage – A type of strong, relatively inelastic connective tissue.
• fibroma – A benign tumor formed in fibrous or connective tissue.
• fibromatosis – A thickening and invasive growth in tendon sheaths.
• fibropapillomatosis – A condition characterized by the presence of abnormal growths of tissue (fibrous papillomas) in both the epidermal and dermal skin layers.
• fibrosarcoma – A malignant tumor that arises from cells that produce connective tissue, predominantly found in the area around bones or in soft tissue.
• fibrosis – The formation of excessive, dense, tough connective tissue.
• fibrous osteodystrophy – Generalized loss of mineral salts throughout the skeleton due to an increased rate of bone destruction resulting from hyperparathyroidism (excess parathyroid hormone secretion). Also known as osteitis fibrosa cystica.
• fibrous tissue – Tissue consisting primarily of high-strength fibers, such as ligaments and tendons.
• filly – A young female horse.
• filtration – The process of removing waste and particulate matter from water.
• first aid – Emergency medical treatment given until more thorough, professional veterinary treatment can be obtained.
• fistulous withers – A condition in which connective tissue in a horse’s withers region becomes infected and inflamed.
• flagellate – A single-celled organism with one or more flagella, whip-like appendages used for locomotion.
• flashing – Scratching (as pertains to fish).
• flea – A small, wingless insect that lives on the skin of mammals or birds and feeds on their blood.
• flexor tendons – Any of several tendons that act to bend a joint.
• flora – Bacteria that normally live in a part of the body, such as the intestines.
• fluke – Any of almost 6,000 species of parasitic flatworms.
• fluorescein staining – A test that uses orange dye (fluorescein) and a specialized light to detect foreign bodies or scratches in the eye.
• fly strike – A condition in which flies lay their eggs on wounds, dead skin, or skin covered with feces. The maggots that hatch can destroy large areas of skin. Also called cutaneous myiasis.
• foal – The offspring of a horse or other equid, up to the age of 1 year.
• forceps – A surgical instrument used to grasp and hold tissue.
• forebrain – The front segment of the brain that includes the cerebrum, thalamus, and hypothalamus.
• foreskin – The loose fold of skin that covers the glans of the penis. Also called prepuce.
• fossorial species – An animal that is specially adapted for digging.
• fracture – The partial or complete break of a bone.
• frostbite – Tissue damage caused by freezing temperatures, which can result in tissue death if exposure is extensive.
• fry – Newly hatched fish.
• fungal – Caused by, or related to, a fungus.
• fungus – A classification of living things that are immobile but cannot gain energy from sunlight, as plants can; some cause infections in animals and people.
• fur mite – External parasites that live on the skin and fur and cause itching.
• fur slip – A condition in chinchillas in which patches of fur are lost due to rough handling or fighting.

G

• gait – The manner of walking or moving.
• gastrin – A hormone that prompts the release of gastric acid in the stomach, usually secreted by the stomach and small intestine.
• gastrinoma – A tumor of the pancreatic islet cells.
• gastroenteritis – Inflammation of the stomach and intestine, often resulting in diarrhea, vomiting, and cramps.
• gastrointestinal – Having to do with the stomach and intestines.
• gastrointestinal system – The internal organs responsible for digestion, including the stomach and the intestines.
• gastrostomy – Insertion of a tube directly into the stomach for the purpose of providing nutrition.
• genetic – Having to do with genes or heredity.
• genitalia – External sex organs.
• geotrichosis – A rare fungal infection caused by Geotrichum candidum, a fungus found in soil, decaying organic matter, and contaminated food.
• gestation – The period of development of an animal inside its mother’s womb.
• Giardia – A water-dwelling, single-celled microorganism that causes diarrhea in many species, including humans.
• giardiasis – A gastrointestinal disorder caused by infection with Giardiamicroorganisms, characterized by diarrhea, stomach cramps, nausea, and vomiting.
• gingivitis – Inflammation of the gums.
• glanders – A contagious, incurable, slowly progressive bacterial infection of horses that may affect the skin or lungs. Also called farcy.
• glaucoma – An eye disorder marked by increased pressure within the eye, which can damage the interior of the eye and lead to blindness.
• gliding membrane – A flap of skin which allows an animal to glide but not fly, as is found in sugar gliders and flying squirrels. Also called a patagium.
• globin – A globular protein that combines with heme to form hemoglobin.
• glomerulonephritis – Inflammation of the glomeruli of the kidney.
• glomerulonephrosis – A common disease of older rats involving inflammation of the blood vessels in the kidney.
• glomerulus – Structure in the kidney made up of special blood vessels that help filter blood; each kidney contains thousands of these.
• glossitis – Inflammation of the tongue.
• glucagon – A hormone that helps convert stored carbohydrates into glucose (sugar) so they can be used as energy.
• glucocorticoid – A type of corticosteroid (seecorticosteroid) that is involved with metabolism of carbohydrates, protein, and fat. They are frequently used in medicine for their anti-inflammatory and immuno-suppressive properties.
• glucose – A simple sugar that is one of the body’s main sources of energy.
• glucosuria – The presence of glucose, a sugar, in the urine.
• gnat – A small, 2-winged biting fly.
• goiter – An enlarged thyroid, often caused by iodine deficiency.
• goitrogen – A goiter-producing substance.
• gonads – The sex organs that produce reproductive cells (sperm and eggs). In the male, these are the testes; in the female, the ovaries.
• gout – A painful inflammation of joints, often in the foot, that is most often caused by a buildup of uric acid and salts.
• granule – A small grain or particle; or a compound of powder particles that have been formed into larger pieces.
• granulocyte – A specialized type of white blood cell, produced in the bone marrow, that plays a role in immune responses to invading microorganisms.
• gray patch disease – A herpesviral infection of the skin that affects turtles, characterized by sores that spread across the turtle’s body.
• growth plate – Zone of cartilage near the ends of long bones where new bone is formed.
• gut loading – The process of feeding prey animals highly nutritious food in order to pass the nutrients on to animals that eat them.
• guttural pouch – Areas of the eustachian tubes that form a bag or pouch, located under the base of the skull in horses.

H

• habituation – A simple form of learning that involves the ending of, or decrease in, a reaction to a situation as a result of repeated or prolonged exposure to that situation.
• halogenated – Combined or treated with a halogen (fluorine, chlorine, bromine, iodine).
• hardpad disease – Seecanine distemper.
• head tilt – A condition in which the head is kept tipped to one side; can be caused by many different diseases, including inner ear infection and neurological problems.
• heart disease – Any structural or functional abnormality of the heart that impairs its normal functioning.
• heart failure – Any heart abnormality that results in failure of the heart to pump enough blood to meet the body’s needs.
• heat – 
• heat exhaustion – A condition caused by overexertion in high temperatures or overexposure to the sun.
• heat stroke – A collapse brought on by prolonged periods of heat stress or heat exhaustion. Signs include cessation of sweating or panting, extremely high body temperature, and unconsciousness.
• helminth – A general term for a group of parasitic worms.
• hemangiosarcoma – A rare, rapidly growing, highly invasive cancer that originates from cells that line blood vessels (endothelial cells).
• hematology – The study of blood, its chemistry and components.
• hematoma – A mass of blood, generally clotted, that forms in an organ or body cavity due to a ruptured blood vessel.
• hematopoiesis – The formation and development of the various blood cells.
• heme – A complex molecule containing iron that combines with globin to form hemoglobin.
• hemoglobin – The iron-rich compound in blood that carries oxygen throughout the body.
• hemolysis – A condition in which red blood cells are ruptured.
• hemorrhage – Bleeding; escape of blood from a broken blood vessel.
• hemostasis – A process that stops blood flow, particularly clot formation.
• hemostatic – A compound that inhibits bleeding.
• hepatic – Related to or affecting the liver.
• hepatic encephalopathy – A syndrome that occurs as a result of liver disease; signs include circling, head pressing, aimless wandering, weakness, poor coordination, blindness, excessive drooling, aggression, dementia, seizures, and coma.
• hepatitis – Inflammation of the liver.
• hepatopathy – General scientific term for liver disease.
• herbicide – One of a group of chemicals used to destroy weeds.
• herbivores – Animals, such as rabbits or horses, that eat only plants.
• hereditary – Transmitted genetically from parent to offspring.
• hernia – The protrusion of a body part through the lining that normally encloses it.
• herpesvirus – Any of a group of viruses that cause disease in humans and animals. Herpesviruses often cause sores or rashes and generally remain in the body even when not causing signs.
• hibernation – A state of inactivity and unconsciousness, generally during the winter months.
• histiocytoma – A soft tissue giant cell tumor.
• histology – The anatomical study of the microscopic structure of tissue.
• histoplasmosis – A noncontagious infection caused by a soil fungus, occurring when airborne spores are inhaled.
• hives – The least severe type of anaphylactic (allergic) reaction. Small bumps occur on the skin. The hair may stand up over these swellings and sometimes they itch.
• hock – The ankle joint of rabbits, horses, and other 4-legged animals that walk on the same bones that form the toes in humans.
• hormone – A compound produced by a gland in the body that stimulates other parts of the body and controls their activity.
• host – A living animal or plant on or in which a parasite lives.
• hot packing – A supportive treatment that involves application of moist heat to reduce inflammation.
• human-animal bond – The emotional relationship existing between humans and companion animals.
• husbandry – The care provided to maintain domestic animals.
• hutch – A pen or coop for a small animal, such as a rabbit.
• hutch burn – A disease caused by wet and dirty hutch floors in which the area surrounding the anus and genital region becomes inflamed and chapped, and then infected with disease-causing bacteria.
• hydration – The process of providing an adequate amount of fluids to body tissues.
• hydrocephalus – A condition in which excess fluid accumulates within the skull because of a blockage in the normal channels that allow it to flow out of the skull.
• hygiene – Actions taken to maintain cleanliness and health.
• hygroma – A cyst or sac filled with fluid.
• hyper- – Prefix meaning over, above, too much, too high, excessive.
• hyperadrenocorticism – A disease caused by production of too much cortisol. Also called Cushing’s disease.
• hypercalcemia – Abnormally high levels of calcium in the blood, characterized by weakness, nausea, confusion, and lethargy.
• hyperextension – Extension of a joint beyond its normal range of motion.
• hyperlipemia – Excessive levels of fat in the blood.
• hyperparathyroidism – An excess of parathyroid hormone in the blood.
• hyperplasia – An abnormal increase in the number of cells in an organ or tissue with consequent enlargement.
• hypertension – An increase in the body’s blood pressure.
• hyperthermia – Abnormally high body temperature.
• hyperthyroidism – A disorder caused by an excess of the thyroid hormones.
• hypertrichosis – A common endocrine disorder resulting from chronic excess of the hormone cortisol (Cushing’s disease). Signs include development of an abnormally long or heavy hair coat, excessive thirst and urination, increased appetite and weight, an enlarged abdomen, and bulging eyes.
• hypertrophy – Enlargement of an organ or tissue.
• hyperuricemia – Abnormally high levels of uric acid in the blood, caused by excessive production or insufficient excretion of the compound.
• hypo- – Prefix meaning below, less than normal, deficient, too little, too low.
• hypoadrenocorticism – A deficiency of adrenal gland hormones. Also called Addison’s disease.
• hypocalcemia – Abnormally low levels of calcium in the blood.
• hypoglycemia – Abnormally low levels of glucose in the blood, often caused by a deficiency of insulin, characterized by trembling, weakness, hunger, confusion, unconsciousness, and in severe cases, death.
• hypoparathyroidism – Disorder characterized by low calcium levels, high phosphate levels, and either temporary or permanent insufficiency of parathyroid hormone.
• hypoplasia – A condition of abnormal development in which a body part remains small, immature, or underdeveloped.
• hypoproteinemia – Abnormally low levels of protein in the blood.
• hypothalamus – The part of the brain below the thalamus that functions to regulate bodily temperature and certain metabolic processes.
• hypothermia – Abnormally low body temperature.
• hypothyroidism – A deficiency of thyroid hormone, which can cause weight gain, constipation, and cold sensitivity.
• hypoxia – Condition in which the level of oxygen in the blood is too low; anoxia.

I

• idiopathic – Used to describe a disorder or disease that has no apparent cause.
• immersion – A method of administering medication to or treating fish by placing them in a tank containing the medication.
• immune – Resistant to infection or disease.
• immune response – The body’s reaction to an infectious agent or other foreign “invader.” This includes recognition of the invader and development of a protective defense.
• immune system – The system within an animal that recognizes an infectious agent or other foreign “invader” and mounts an immune response. The immune system includes various organs, such as the thymus gland, spleen, and lymph nodes, as well as specialized cells found throughout the body.
• immune-mediated – Describes a process initiated or controlled by the immune system.
• immunization – The process of making an individual immune to a given disease, generally through vaccination.
• immunized – Rendered resistant to toxins or infectious agents, especially by injection or vaccination.
• immunodeficiency – An inability of the immune system to produce a normal immune response.
• immunoglobulin – Protein antibodies produced by the body to fight a disease.
• immunomodulator – A drug that helps regulate the immune system’s activity.
• immunostimulant – A drug or agent that increases an immune response.
• immunosuppressed – A state in which the immune system is inhibited by medications during the treatment of other disorders, or by stress or infection.
• immunosuppression – Interference with the normal function of the immune system.
• immunotherapy – Any of several treatments of disease that involve inducing, enhancing, or suppressing an immune response.
• impedance – Obstruction of normal flow or passage, such as an obstruction of blood flow.
• implant – A drug, such as a long-lasting tablet, inserted under the skin.
• incisor – Front teeth that are used to grasp or cut food.
• inclusion body disease – Any disease characterized by inclusion bodies, small foreign bodies within cells.
• incontinence – The inability to control urination or defecation.
• incubation period – The time after an infection has been contracted but before any signs are apparent.
• infection – A disorder that occurs when microorganisms invade the body and multiply. Infectious microorganisms include bacteria, viruses, fungi, and parasites.
• infectious – A condition that is passed from animal to animal by a virus, bacterium, or other agent.
• infectious canine hepatitis – A contagious viral disease of dogs with signs that vary from a slight fever and congestion of the mucous membranes to severe depression, severe reduction in white blood cells, and deficiency of blood clotting.
• infertility – The inability to produce offspring.
• infest – To live as a parasite in or on.
• infestation – The act of infesting or state of being infested.
• infiltrate – Material deposited within the space between cells in a tissue.
• inflammation – A localized protective response to injury or other tissue damage. The response includes increased blood flow in the surrounding capillaries (causing redness), swelling, increased temperature in the area, and pain.
• inflammatory – Characterized or caused by inflammation.
• influenza – A respiratory infection caused by an influenza (flu) virus.
• ingest – To take food or liquid into the body by swallowing or absorption; eat.
• inhalation – The act of breathing in.
• inherited – Passed genetically from parents to offspring.
• inhibitor – A substance that restrains or retards physiological, chemical, or enzyme action.
• initiation – The first step in the transformation of healthy cells into cancerous cells.
• inoculation – Introduction of a substance into the tissues or fluids of the body; this is often done for the purpose of preventing or curing certain diseases.
• inorganic – Composed of minerals rather than living material; without carbon.
• insect growth regulator – A class of drugs that helps control pests such as fleas by disrupting their development and maturation.
• insecticidal – Of or related to a chemical substance used to kill insects.
• insulin – A hormone secreted by the pancreas that is essential for digestion, especially that of carbohydrates. See alsodiabetes mellitus.
• insulinoma – A common pancreatic islet tumor that affects the insulin-secreting beta cells.
• interdigital furunculosis – Abscesses on the webbing between the toes.
• interferon – Protein produced by immune cells that helps fight viral infection. See also
• intermediate host – An animal in which juvenile parasites reside before passing to the final host animal to develop into adults and breed.
• intestinal protozoan – Any of a number of single-celled microorganisms that infect or dwell within the intestines. Many cause disease, but others are harmless or even beneficial.
• intestine – The part of the digestive tract between the stomach and the anus, divided into the small intestine and the large intestine.
• intoxication – Another term for poisoning or toxicosis.
• intramuscular – Directly in or into the muscle.
• intraocular – Having to do with, entering, or residing within the interior of the eye.
• intravascular – Inside the blood vessels.
• intravenous – A method of administering fluids or medications directly into a vein. Also known by the abbreviation IV.
• intubation – Insertion of a breathing tube into the trachea.
• intussusception – The doubling up of a section of intestine on itself in accordion-like folds, causing obstruction.
• invasive – A tumor that tends to spread locally into adjacent tissues.
• invertebrate – An animal without a backbone, such as an insect or spider.
• involuntary – Spontaneous or automatic; not controllable by the conscious mind.
• iodine deficiency – Insufficient iodine in the diet that can lead to goiter.
• iodine toxicity – Harmful effects, which may include goiter, of an excess of iodine in the diet.
• iris – The muscular diaphragm in the eye that controls the size of (and therefore the amount of light passing through) the pupil.
• irradiation – Bombardment with radiation, generally as a treatment for tumors.
• islet cell tumor – A cancer of the islet cells of the pancreas.
• islet of Langerhans – Cluster of 3 kinds of endocrine cells scattered throughout the pancreas that secrete several hormones, including insulin.
• isolation – The process of keeping diseased or potentially diseased animals separate from other susceptible animals.

J

• jaundice – A condition characterized by yellowing of the skin, eyes, and mucous membranes caused by an excess of bile products in the blood.
• joint – The site where 2 or more bones meet. Joints may be movable or immovable.
• joint mice – Fragments of cartilage in joints.
• jugular – Of, relating to, or located in the region of the neck or throat.

K

• keratin – The hard protein that makes up hair, fingernails, claws, horns, scales, and the shafts of feathers.
• keratinization – Creation of new skin cells near the base of the epidermis that migrate upwards, producing a compact layer of dead cells on the skin surface.
• keratoacanthoma – A benign skin tumor of dogs that includes a cyst filled with keratin.
• ketosis – A condition resulting from excess buildup of ketones, a waste product, in the blood.
• kidney – Either of a pair of abdominal organs that filter waste from the blood and help maintain proper water and salt balance.
• kidney failure – Loss of normal function of the kidneys, which can be either a short- or longterm condition.
• kit – The young of any of a number of mammals, such as foxes and rabbits.

L

• laceration – A cut or tear in the skin.
• lacrimal gland – The gland near the eye that produces tears.
• lactation – The production of milk by a female mammal.
• Lactobacillus species – A group of bacteria that create lactic acid and play a normal, often beneficial, role in many animals’ bodies.
• lagenidiosis – A fungal infection of dogs that affects the skin and blood vessels.
• lagophthalmos – An inability to completely close the eyelids due to malformation.
• lameness – An inability to walk or move normally, often, but not always, caused by pain in the limb.
• larva – An immature form or life stage of an insect or parasite.
• larvae – Plural form of the word larva.
• larval – Of or pertaining to larvae.
• larynx – The part of the throat often called the “voice box” in humans.
• latent – In an inactive or hidden stage.
• laxative – A drug used to promote bowel movements.
• leg banding – The process of putting coded bands onto the legs of captive birds, generally while they are young, for purposes of identification.
• Legg-Calvé-Perthes disease – Deterioration of the top of the femur (the femoral head) seen in young miniature and small breeds of dogs, characterized by a lack of blood supply and destruction of blood vessels of the bone.
• lens – The transparent, oval-shaped part of the eye that focuses light on the retina.
• leptospirosis – An infection characterized by fever and jaundice caused by bacteria of the genus Leptospira.
• lesion – Any abnormal change in the structure or function of a part of the body.
• lethargy – Lack of energy; apathy.
• leukemia – A cancer of the blood and bone marrow, characterized by increased numbers of white blood cells.
• leukocyte – Blood cell type involved in immune responses; commonly called white blood cells.
• leukocytic – Having to do with leukocytes.
• leukocytosis – An increase in the number of white blood cells in the bloodstream.
• leukogram – A diagnostic blood test that counts the number of different white blood cells circulating in the bloodstream.
• leukopenia – A decrease in the number of white blood cells in the bloodstream.
• libido – Sexual drive; desire to mate.
• lice – A group of small, wingless insects that live on the skin of birds and mammals and suck their blood.
• life cycle – A description of all the stages in the life of an organism.
• ligament – A band of tough, fibrous tissue connecting bones or cartilage at a joint, or supporting an organ.
• liposarcoma – A benign tumor of fatty tissue.
• listeriosis – An infection by the bacteria Listeria monocytogeneswhich can affect the nervous system, or lead to abortion or blood poisoning.
• liver – A large abdominal organ with many functions, such as filtering and removing toxins from the blood, storing glycogen, and producing and secreting bile.
• localized – Restricted or limited to a specific body part or region.
• lockjaw – A spasm of the jaw muscles that keeps them tightly closed, most frequently caused by tetanus. See also
• long bones – Any of several elongated bones of the legs (for example, the femur and humerus) that have a roughly cylindrical shaft.
• lordosis – An abnormal inward curving of the spine in the lower area of the back.
• lumpectomy – Surgical excision of a tumor with minimal removal of surrounding tissue.
• lumpy jaw – The most common and least severe form of actinomycosis, a bacterial infection that causes hard masses to form in the mouth and jaw.
• lung – Either of 2 spongy, saclike respiratory organs that occupy the chest cavity and provide the blood with oxygen while removing carbon dioxide during respiration.
• luxation – 
• Lyme disease – Tickborne infection of animals and humans caused by Borrelia burgdorferibacteria that can cause rash and arthritis. Also known as Lyme borreliosis.
• lymph node – Small organ of the immune system that contains cells that fight infections, neutralize toxins, and produce antibodies.
• lymph – A clear, watery fluid derived from body tissues that collects through the lymphatic system and is then returned to the bloodstream.
• lymphadenitis – Inflammation of the lymph nodes.
• lymphangitis – Inflammation of lymphatic vessels.
• lymphatic system – The network of small vessels that collects the fluid surrounding the cells and returns it to the bloodstream.
• lymphocyte – White blood cells that produce antibodies, neutralize toxins, and fight infections and cancer.
• lymphocytic choriomeningitis – A viral infection of mice characterized by fever, vomiting, neck stiffness, and slow pulse.
• lymphocytosis – An increase in the number of lymphocytes in the bloodstream.
• lymphoid – Of or relating to the lymph or lymphatic tissue.
• lymphoma – A cancer of certain white blood cells that begins in a lymph node or other lymphoid tissue.
• lymphopenia – A decrease in the number of lymphocytes in the bloodstream.

M

• macrophage – A type of white blood cell, larger than most, that consumes infectious agents and other foreign cells and destroys them.
• maggot – The legless, soft-bodied, wormlike larva of any of various flies, often found in decaying matter.
• magnetic resonance imaging (MRI) – An advanced, noninvasive diagnostic imaging technique that uses powerful magnets to examine tissues and organs.
• malabsorption – Faulty or abnormal absorption of nutrients from the digestive tract.
• malaise – A feeling of illness or depression.
• maldigestion – Abnormal breakdown and absorption of foods from the digestive tract.
• malignant – Cancerous; a tumor that invades other nearby tissues or spreads throughout the body.
• malnourished – Affected by an improper or insufficient diet; undernourished.
• malocclusion – Seedental malocclusion.
• mammals – Animals that produce milk to feed their young and have 4 limbs and at least some hair.
• mammary – Of or relating to the mammary glands of a female mammal.
• mammary glands – The organs that produce milk.
• mange – Any of several skin disorders caused by an infestation of mange mites.
• marking – Depositing urine or feces to send a social signal, such as claiming territory.
• marsupials – Mammals, chiefly but not exclusively from Australia, that carry their young in an external pouch.
• masking behavior – Behavior to hide injury or weakness, especially by prey animals.
• mass – Another word for a tumor or growth.
• mast cell – A cell that secretes histamine found in connective tissue.
• mastitis – Inflammation of the mammary glands, often caused by bacterial infection.
• maternal immunity – The resistance to disease provided by antibodies passed through the mother’s first milk (colostrum) to newborn mammals, usually lasting for several weeks.
• mechanism – A process by which something is accomplished.
• megakaryocyte – A large cell found in bone marrow that produces platelets.
• melanoma – A type of skin tumor, often malignant, that contains dark pigment.
• melioidosis – An uncommon bacterial infection, usually of rodents, that can be passed to humans.
• membrane – A thin layer of tissue that lines an organ or body cavity.
• meninges – Thin layers of tissue that line the brain and spinal cord.
• meningitis – Inflammation of the meninges.
• meningoencephalitis – Inflammation of the brain and of the membrane lining the brain and spinal cord.
• metabolic activity – The chemical processes occurring within a living cell or organism that are essential to maintenance of life.
• metabolic bone disease – Any of several diseases of the bones caused by an imbalance of calcium and other minerals in response to abnormal metabolism.
• metabolic disorder – Any disorder in which normal body processes are disturbed, leading to an increase or decrease in the end products of those processes.
• metabolic rate – Metabolism over time; the speed at which metabolism occurs.
• metabolism – The physical and chemical processes that take place in the body to maintain life.
• metacarpal bones – Bones in a vertebrate animal’s forefoot similar to the bones in the human hand between the wrist and the fingers.
• metastasis – The spread of a malignant tumor to distant parts of the body.
• metastatic calcification – Abnormal, hardened deposits of calcium in soft tissues.
• metastatic tumor – A tumor formed from cells that have traveled from the original tumor to another site in the body.
• metatarsal bones – Bones in a vertebrate animal’s hind foot similar to bones in the human foot between the toes and the ankle.
• metritis – Inflammation of the uterus.
• microbiology – The study of small organisms such as bacteria, viruses, fungi, and other single-celled life forms.
• microchipping – A method of identifying pets that involves the insertion of a small glass-encased electronic chip under the skin.
• microfilaria – Immature life stage of heartworms that is found in the bloodstream.
• microhabitat – The small, specialized environment in which an organism lives.
• microorganism – A bacterium, virus, or other organism that is too small to see without a microscope.
• midges – Gnatlike flies that are often found near water; some species bite and feed on blood.
• miliary dermatitis – Skin irritation with small, solid, bumps typically spread over the back, neck, and face.
• mineralocorticoids – Hormones produced by the adrenal cortex that help control the body’s balance of sodium and potassium salts.
• mineral – A solid crystalline substance arising from inorganic processes. Many minerals are nutrients that are needed for normal body functions.
• mite – Any of a number of very small arachnids, related to spiders and scorpions, many of which live as parasites on various species of animals.
• mitral valve – The valve between the left chambers of the heart, through which the blood flows from the atrium to the ventricle.
• molar – A large grinding tooth in the back of the mouth.
• mold – Any of various fungi that often cause disintegration of organic matter.
• molt – In birds, the normal loss of feathers in preparation for the growth of new feathers. In reptiles, the normal shedding of skin; also called ecdysis.
• Mongolian desert mice – Another term for gerbils, related to their origin.
• monkeypox – A viral disease, similar to but milder than smallpox, originally detected in monkeys.
• monocyte – A type of white blood cell that plays a role in immune defense by moving from the bloodstream into the tissues, enlarging, and becoming a macrophage. See also
• monocytopenia – A decrease in the number of monocytes in the bloodstream.
• monocytosis – An increase in the number of monocytes in the bloodstream.
• mortality – The rate of death in a population.
• mosquito – A winged insect that feeds on blood and can transmit disease.
• motor – Relating to motion, or body movement.
• motor function – The ability to produce body movement by complex interaction of the brain, nerves, and muscles.
• motor neurons – Nerve cells that carry signals from the brain that control muscle activity.
• MRI – Seemagnetic resonance imaging.
• mucosa – Seemucous membrane.
• mucous membrane – The layer of cells that lines the tubular organs of the body, such as the digestive and respiratory tracts.
• mucus – A slippery secretion produced by glands of the mucous membranes.
• multifocal – Relating to or arising from many locations.
• murmur – A vibration heard coming from the heart or major blood vessels.
• muscle – A tissue composed of fibers capable of contracting (and thus producing motion).
• muscular wasting – The steady loss of muscle mass and strength.
• musculoskeletal – Having to do with the muscles, bones, and joints.
• Mustelidae – Latin term for the scientific family that includes ferrets, mink, and skunks.
• mutation – A spontaneous, permanent change in genetic material that is passed to the organism’s offspring.
• muzzle – An animal’s nose and jaws.
• mycetoma – Infection of the skin and underlying tissues that has the appearance of a nodule or tumor.
• mycobacterial infections – See
• mycobacteriosis – Infection by mycobacteria, a group that includes the bacteria responsible for leprosy and tuberculosis.
• mycoplasma – The smallest known type of bacteria, which lack cell walls.
• mycosis – Fungal infection.
• mycotoxicosis – Disease caused by toxins produced by fungi.
• myelography – A specialized x-ray procedure in which a dye is injected into the cerebrospinal canal to outline the spinal cord.
• myiasis – Maggot infestation. Also known as strike.
• myocardial disease – A disorder of the heart muscle.
• myocarditis – A local or widespread inflammation of the heart muscle with degeneration or death of the heart muscle cells.
• myocardium – The muscular tissue of the heart.
• myopathy – General term referring to any skeletal muscle disease.
• myositides – Diseases that produce a mainly inflammatory reaction in muscle.
• myositis – Inflammation of a muscle, characterized by pain, tenderness, and sometimes spasm in the affected area.
• myxomatosis – A severe viral disease in rabbits, characterized by the formation of myxoma, or soft, gelatinous tumors, and subsequent swelling around the head, face, and genitals.

N

• nagana – An often fatal disease of vertebrates transmitted by the bite of the tsetse fly; may affect multiple body systems and often causes anemia.
• nares – The openings of the nose.
• nasal – Having to do with the nose, often its interior.
• nasal cavity – The air-filled space above and behind the nose, on either side of the septum.
• nasal discharge – Material, typically mucus, emerging from the nose.
• nasogastric tube – A feeding tube that is inserted through the nose into the stomach.
• nasolacrimal duct – A duct that moves tears from the eye to the nose.
• nebulization – Conversion of a substance, such as a medication, from a liquid or solid state into a fine mist or vapor.
• necropsy – An animal autopsy.
• necrotic dermatitis – Inflammation of the skin characterized by localized death of tissue.
• necrotic meningoencephalitis – A disease caused by infection of the brain with microorganisms, with signs that may include depression, lethargy, labored breathing, loss of appetite, bluish skin, and a pus-like discharge from the nose.
• nematode – A parasitic worm; also called a roundworm.
• neonatal – Having to do with newborn offspring.
• neoplasia – The formation of a tumor.
• neoplasm – A tumor.
• neosporosis – An infectious disease of dogs and other animals caused by the protozoan parasite Neospora caninum.
• nephritis – Inflammation of the kidney.
• nephrotic – Of or relating to the kidneys.
• nephrotic syndrome – Signs of disease in the kidney that may include protein in the urine, low levels of protein in the blood, a buildup of fluid in the abdomen, shortness of breath, and swelling in the legs.
• nerve – Specialized tissues that transmit electrical impulses serving to relay sensory or motor information between the nervous system and body organs.
• nest box – A man-made box provided for animals to nest in.
• neuroendocrine tissue tumors – Tumors that can develop from neuroendocrine cells (found in tissues that have both nervous system and hormone-producing functions) in the adrenal or thyroid glands.
• neurologic – Of or pertaining to the nervous system.
• neurologic signs – Impairments of perception or behavior caused by damage to the central nervous system.
• neuromuscular – Having to do with the terminations of nerves in muscle tissue.
• neuron – The specialized cells of the nervous system responsible for transmitting electrical signals.
• neuropathic pain – Pain resulting from damage to a nerve or some other part of the central nervous system.
• neurotransmitter – A chemical released by a nerve cell that passes signals to other nerve cells, or to muscles or glands.
• neuter – To remove the internal reproductive organs (that is, the ovaries and uterus or testes) of an animal in order to prevent reproduction.
• neutropenia – A decrease in the number of neutrophils in the bloodstream.
• neutrophil – A common type of white blood cell that engulfs and destroys bacteria and other foreign cells.
• neutrophilia – An increase in the number of neutrophils in the bloodstream.
• nevus – A congenital pigmented area on the skin; sometimes called a birthmark.
• Newcastle disease – A contagious viral disease in birds, whose signs include coughing, sneezing, diarrhea, tremors, and twitching.
• nictitating membrane – A thin membrane in many animals that can extend across the eye to protect it; also called the third eyelid.
• nit – The small egg of a louse, typically found glued to hair.
• nitrates – Chemical compounds that can be used by plants and algae as food, or removed by water filtration.
• nocardiosis – A chronic, noncontagious disease caused by Nocardiabacteria found in soil, decaying vegetation, and other environmental sources.
• nocturnal – An animal that is active only or primarily at night.
• nodule – A small, irregular, rounded mass.
• noncontagious – Not contagious; not communicable by contact.
• nonregenerative anemia – A decrease in the number of red blood cells, which the bone marrow is not able to fully compensate for by creating new red blood cells.
• nonsteroidal anti-inflammatory drug (NSAID) – A group of medications other than corticosteroids that relieve pain, fever, and inflammation.
• nonviremic – Animals that, despite being infected by a virus, show no evidence of it in the bloodstream.
• nuclear scintigraphy – A diagnostic procedure involving dosing the animal with a radioactive element. This element is then detected within the body by means of a special camera attached to a computer, which generates the image.
• nutrient – A substance that nourishes a living thing.
• nutrition – A source of nourishment; food.
• nutritional deficiency – A lack in the type or amount of nutrients an organism receives.
• nutritional osteodystrophy – Defective bone formation, as in rickets, caused by an imbalance of calcium and phosphorus in the diet.
• nymph – The larval form of certain insects.
• nymphomania – Prolonged estrus or sexually receptive behavior in a female animal.
• nystagmus – Abnormal, involuntary, usually rapid movement of the eyeballs as a result of dizziness, head injury, or disease.

O

• obstruction – Blockage of a passage in the body, as of the intestines.
• ocular – Of or relating to the eye.
• ocular fundus – The back layer of the eye opposite the pupil where light is detected by specialized nerve cells.
• ointment – A healing salve intended for external application.
• oncologist – A cancer specialist.
• oncology – The field of medicine dedicated to the study, diagnosis, and treatment of cancer.
• oocyst – A fertilized egg in the process of development; a zygote.
• oomycosis – Infection with Oomycetes fungi, most common among fish.
• opaque – Something through which light cannot pass.
• ophthalmoscope – An instrument for viewing the interior of the eye.
• opiate – A class of narcotic drugs derived from opium that can reduce pain, induce sleep, and suppress coughing.
• opioid – Any of a class of synthetic drugs that are not derived from opium but have similar properties. See
• opportunistic agent – An infectious substance or microorganism, not normally dangerous, that can cause disease when the body’s immune system is impaired or weakened.
• opportunistic infection – An infection by a microorganism that normally does not cause disease but becomes capable of doing so when the body’s immune system is impaired or weakened.
• optic disk – The point on the retina where the optic nerve enters the eye. Also called the blind spot.
• optic nerve – The nerve that connects the eye to the brain and transmits visual information; also called the second cranial nerve.
• optimal temperature zone – The preferred temperature range for a species.
• oral – Having to do with the mouth.
• oral cavity – The interior of the mouth.
• orbit – The part of the skull that encloses and protects the eye and related structures.
• organ – A structure composed of various types of tissues that has a specific function; most organs function as part of an organ system.
• organic – Relating to a substance derived from a living organism; containing carbon.
• organism – An individual form of life, such as a plant, an animal, a bacterium, or a fungus.
• osmoregulation – Maintenance of an optimal balance in the concentration of salts in the body’s fluids.
• osteoarthritis – Seedegenerative joint disease.
• osteochondritis dissecans – A condition usually seen in young animals in which the immature joint cartilage separates from the underlying bone.
• osteochondrosis – A condition in which immature joint cartilage separates from the bone and floats loosely in the joint cavity, where it can cause inflammation and interfere with proper bone formation.
• osteomalacia – A condition in adult animals in which the bones soften because of an imbalance in calcium and phosphorus metabolism.
• osteomyelitis – Inflammation of the bones caused by a bacterial infection.
• osteoporosis – A condition marked by loss of bone mass due to poor nutrition, age, or nursing.
• osteosarcoma – A malignant bone tumor.
• otitis – Inflammation of the ear.
• otitis externa – Inflammation of the external ear canal.
• otitis interna – Inflammation of the inner ear.
• otitis media – Inflammation of the middle ear.
• otoscope – An instrument with a light and a magnifying lens to aid visual examination of the ear canal.
• outbreak – A sudden occurrence or appearance, as of a disease.
• ovary – The female reproductive organ that produces eggs, as well as the hormones estrogen and progesterone.
• ovariohysterectomy – The surgical removal of the ovaries and uterus.
• over-the-counter – Sold directly to the public without a doctor’s prescription.
• ovulation – The release of an egg (ovum) from the ovary for possible fertilization.
• oxygenate – To treat, combine, or infuse with oxygen.
• oxytocin – A hormone that stimulates milk flow, causes the uterus to contract during and after birth, and increases maternal behavior.

P

• paecilomycosis – An infection caused by fungi of the genus Paecilomycesthat affects the lungs and other organs.
• palliative – A drug or medicine used to relieve or soothe the signs of disease.
• palpation – Examination by finger pressure to detect growths, changes in underlying organs, and unusual tissue reactions to pressure.
• pancreas – A large gland that secretes digestive enzymes and hormones, such as insulin, that regulate blood sugar levels.
• panhypopituitarism – A disorder in which the pituitary gland and nearby tissues, including the hypothalamus, are compressed or damaged, leading to a lack of several different hormones.
• papilloma – A wart or other benign growth on the skin or other vascular tissues.
• papillomatosis – Any condition marked by the presence of many papillomas. See
• papule – A small, hard, round bump or protuberance on the skin.
• paralysis – Partial or total loss of motor function or sensation in part of the body.
• paramyxovirus – Any of a group of viruses including those that cause measles, mumps, rubella, and Newcastle disease.
• paranasal – Adjacent to the nasal cavity.
• parasite – Any living organism that lives inside, with, or close to another living creature (called a host) and uses the host as a source of food, shelter, or other requirements.
• parasitic – Of, related to, or caused by a parasite.
• parasitism – A close relationship in which one species, the parasite, benefits at the expense of the other, the host.
• parathyroid glands – Glands that secrete parathyroid hormone and calcitonin.
• parathyroid hormone – A hormone that acts with vitamin D and another hormone, calcitonin, to regulate the levels of calcium in the body.
• parvovirus – A family of viruses including a type that causes a highly contagious intestinal disease of dogs.
• passerine – Describes the group of perching birds and songbirds such as jays, blackbirds, finches, warblers, and sparrows.
• paste – A semisolid drug dosage form for treating animals.
• pasteurellosis – Infection with Pasteurellabacteria, which most frequently infect the respiratory tract.
• patagium – Seegliding membrane.
• patella – Kneecap; a flat triangular bone located at the front of the knee joint.
• patellar luxation – Displacement of the kneecap.
• patent ductus arteriosus – A heart defect in which the ductus arteriosus (the temporary fetal blood vessel connecting the aorta and the pulmonary artery) does not close at birth.
• pathogenic – Producing disease, or having the capability to cause disease.
• pathologic – Relating to or caused by disease.
• pathologist – A veterinarian or physician who specializes in examining tissue samples to identify the cause of disease or death.
• pectoral muscle – Any of the muscles that connect to the chest at one end and to the bones of the front limbs at the other end.
• pelvic canal – The passage from the abdomen through the bones of the pelvis to the outside of the body.
• penicillosis – Infection by mold of the genus Penicillium, which usually affects the nose and sinuses.
• penis – The external male organ of copulation, used to transfer semen to the female and to expel urine.
• pentastomes – Worms that infest the respiratory system of birds, reptiles, and mammals. Also called tongue worms due to their appearance.
• perianal – Situated or occurring around the anus.
• pericardial disease – Disease of the pericardium, the sac surrounding the heart.
• pericardiocentesis – Insertion of a needle through the pericardium (the sac surrounding the heart) to withdraw fluid.
• pericarditis – Inflammation of the sac or lining around the heart.
• pericardium – The sac-like membrane surrounding the heart.
• periodontal – Of or relating to the gums.
• perioperative – The period immediately before and after a surgical procedure.
• peripheral nervous system – The parts of the nervous system outside of the brain and spinal cord.
• peritoneal cavity – The space between the membranes lining the abdominal cavity and the abdominal organs.
• peritoneal lavage – Rinsing of the peritoneal cavity with saline or other fluids as a part of a diagnostic test to look for signs of infection or inflammation.
• peritoneum – The membrane lining the abdominal cavity and the organs found within it.
• peritonitis – Inflammation of the peritoneum, often caused by infection or injury to the gastrointestinal tract.
• permeability – The rate at which a liquid or gas passes through a membrane or other porous material.
• persistent – Tenaciously or obstinately continuing, often for a long time.
• pesticide – A chemical that kill pests, especially insects.
• pH – A measure of the acidity or alkalinity of a fluid or damp substance.
• phaeohyphomycosis – A fungal infection that usually occurs because of contamination of tissue at the site of an injury.
• phagocyte – A cell that ingests and kills other substances, especially microorganisms.
• phagocytosis – The process by which cells engulf and digest microorganisms and cellular debris; an important defense against infection.
• phalanx – Any of the bones that form the digits, corresponding to fingers and toes in humans.
• pharmacology – The science that deals with the chemistry, development, uses, and metabolism of drugs.
• pharynx – The throat.
• pheochromocytoma – A tumor of the adrenal gland that is able to secrete adrenaline (epinephrine) and other hormones.
• pheromone – A chemical secreted by an animal that influences the behavior or development of others of the same species; often serving to attract the opposite sex.
• phobia – An intense and excessive fear of something.
• photoperiod – The amount of time per day that an organism is exposed to sunlight or artificial light.
• photoreceptor – Any structure that senses the presence of light.
• photosensitization – A condition in which skin is overly sensitive to sunlight; distinct from sunburn.
• pica – The eating of non-food items, such as gravel or dirt.
• pigmentation – The deposition of coloring matter (pigment) in a cell or tissue.
• pink eye – See
• pinna – The large visible portion of the external ear.
• pinworm – Any of a group of small, parasitic nematodes that live in the intestines of vertebrates.
• piping – Refers to the activity of fish swimming near the surface of the water trying to gulp air.
• pituitary – Related to the pituitary gland of the brain that produces hormones critical for control of many bodily functions.
• pituitary dwarfism – Disorder of the pituitary gland in which a shortage of growth hormone leads to smaller than normal size.
• pituitary gland – A small, oval, endocrine gland attached to the base of the brain which secretes hormones that control many other endocrine glands.
• placenta – The organ that connects the fetus to the mother in most mammals and regulates the exchange of nutrients between them.
• placental – Of or relating to the placenta.
• plague – An acute and sometimes fatal bacterial disease, transmitted primarily by the fleas of rats and other rodents.
• plasma – The clear, yellowish fluid portion of blood or lymph in which cells are suspended.
• plasmodial organisms – Single-celled protozoal parasites that live within the bloodstream and cause malaria.
• platelet – A type of small blood cell responsible for clotting. Also called a thrombocyte.
• pleura – The membranes lining the outside of the lungs and the chest cavity.
• pleural cavity – The space between the membranes lining the chest wall and the lungs.
• pleurisy – Inflammation of the lining around the lungs (the pleura), causing pain, cough, chest tenderness, and shortness of breath.
• pneumonia – Inflammation of the lung tissue, often accompanied by inflammation of the trachea and other large airways; also known as pneumonitis.
• pneumonitis – See
• pneumothorax – Air in the space between the lungs and the chest wall.
• pododermatitis – Inflammation of the skin near the foot or hoof.
• poison – A substance that causes illness, injury, or death if ingested.
• polioencephalomalacia – A neurologic disease that leads to softening and degeneration in the outer layer of the brain.
• poll evil – Bacterial infection and inflammation of a sac surrounding a tendon near the base of the skull in horses.
• polyarteritis nodosa – Inflammation of the walls of arteries that affects multiple organs.
• polycythemia – An increase in the number of red blood cells circulating in the bloodstream.
• polydactyly – The presence of extra toes, which is a common inherited condition in cats.
• polyp – A growth or mass projecting from the tissue of a membrane, sometimes tumorous.
• polyphagia – Excessive appetite or overeating.
• polysaccharide – A complex carbohydrate such as starch or cellulose, made up of sugar molecules in a chain structure.
• porphyrin – A protein molecule that is one of the building blocks of hemoglobin, the molecule that carries oxygen in the bloodstream.
• portosystemic shunt – A congenital defect in the blood vessels of the liver that reduces the ability of the liver to process waste products.
• positive inotrope – Any of a class of drugs used to help the heart muscle contract.
• postpartum hypocalcemia – Seepuerperal hypocalcemia.
• powder – A formulation in which a drug powder is mixed with other powdered fillers to produce a final product.
• predation – The hunting and eating of other animals.
• predilection – A particular liking or preference.
• predisposing factor – A condition or situation that increases the susceptibility to a particular disease or injury.
• pregnancy toxemia – An often-fatal metabolic condition of pregnant guinea pigs, cows, and sheep, more common in those that are overweight, in which a buildup of toxins occurs in the bloodstream.
• prenatal – Of or relating to the period before birth.
• prepuce – A retractable fold of skin covering the penis in many mammals.
• prevalent – Widely or commonly occurring.
• priapism – An abnormal, persistent erection of the penis, often caused by spinal cord injury or injury to the penis.
• primary factor – The main cause, or one of the main causes, of a disease or injury.
• prognathia – Abnormal protrusion of the jaw, commonly the lower jaw.
• prognosis – The prospect of survival or recovery following a disease or injury.
• progressive – Tending to become more severe or wider in scope.
• prokinetic – A drug that increases the movement of food through the gastrointestinal tract.
• prolapse – The displacement of a body part from its usual position.
• proliferative enteropathy – A disease of the intestinal tract in young pigs characterized by severe diarrhea and anemia; possibly caused by bacteria.
• promoter – An agent that facilitates the development of cancer in cells.
• promotion – The second step in the development of cancer.
• prophylaxis – Administering antibiotics as a preventive measure to keep an infection from developing.
• prostate gland – An organ of the male reproductive system that creates part of the fluid portion of semen.
• prostration – Total exhaustion or weakness; collapse.
• protein – Complex molecules made of amino acids that include many substances (such as enzymes, hormones, and antibodies) necessary for the proper functioning of an organism.
• protocol – A method or regimen of treatment.
• protozoa – Plural of protozoan.
• protozoal – Of, related to, or caused by protozoa.
• protozoan – Any of a large group of single-celled, usually microscopic organisms, that may be parasites.
• protrusion – Something that sticks out.
• pruritus – Severe itching; usually signalled by scratching.
• pseudomyiasis – False strike (maggot infestation); the presence of fly maggots in the gastrointestinal tract (from ingestion) but without tissue infestation.
• psittacine – Of or belonging to the family Psittacidae, which includes parrots, macaws, and parakeets.
• psychotropic drug – Any of a group of drugs that are used to modify an animal’s behavior, including antidepressants, anti-anxiety drugs, and sedatives.
• puberty – The phase during which an animal becomes sexually mature.
• puerperal hypocalcemia – A life-threatening decrease in calcium usually seen in dogs 2 to 3 weeks after giving birth, caused by the loss of calcium from producing milk.
• puerperal tetany – Seepuerperal hypocalcemia.
• pulmonary – Of, relating to, or affecting the lungs.
• pulmonary artery – The artery that carries venous blood from the right ventricle of the heart to the lungs.
• pulmonary edema – Fluid in the lungs.
• pulmonary hypertension – High blood pressure in the blood vessels of the lungs.
• pulmonary valve – The valve that releases blood out of the right ventricle of the heart into the pulmonary artery.
• pulse – The rhythmic throbbing of arteries produced by the regular contractions of the heart.
• pupa – The nonfeeding, transformative stage between the larva and adult in insects.
• pupil – The black circle in the center of the iris in the eye; the hole through which light enters the eye.
• pus – A thick, yellowish-white fluid seen in wounds and sores and containing white blood cells, microorganisms, and tissue debris.
• pustules – Small, inflamed, elevations of the skin filled with pus.
• pyloric stenosis – A muscular constriction between the stomach and intestines.
• pyoderma – Any skin disorder that includes formation of pustules or pimples.
• pyometra – A disorder characterized by the accumulation of a large amount of pus in the uterus.
• pythiosis – A disease caused by Pythium insidiosum, an organism similar to a fungus, which can affect the skin or gastrointestinal tract in dogs or cause skin disorders in horses or cats.

Q

• Q fever – A bacterial infection that mainly affects the respiratory or reproductive tracts of ruminants such as cattle and sheep, although other domestic animals, including dogs and cats may be infected. Also known as query fever.
• quadriceps – Large muscle at the front of the thigh that acts to extend the knee.
• qualitative – Of or related to a categorical observation of an object, for example breed or sex.
• quantitative – Of or related to a numerical observation of an object, such as 5 pounds or 3 meters.
• quarantine – To keep an animal separate from other animals to avoid spreading a disease or infection.
• queen – A mature female cat, especially one kept for breeding purposes.

R

• rabbit calicivirus disease – A highly infectious, contagious, and mostly fatal disease of domestic rabbits that affects the digestive system and causes internal bleeding. Also called viral hemorrhagic disease.
• rabbitpox – An often fatal, generalized, viral disease of rabbits that causes pox marks on the skin as well as discharges from the nose and eyes.
• rabbitry – A place where rabbits are kept or bred.
• radiation – High-intensity energy waves emitted by radioactive elements, for example, x-rays.
• radiation therapy – The use of radiation or radioactive substances to treat disease.
• radiography – An imaging technique that produces an image on film or other sensitive surface by radiation, such as x-rays passing through an object.
• radioisotope irradiation – A type of radiation therapy. Seeradiation therapy.
• radiotherapy – Seeradiation therapy.
• radius – The shorter and thicker bone in the lower forelimb of animals.
• radon – A colorless, radioactive gaseous element used in radiotherapy.
• range (as in range plants) – Extensive open land area where livestock wander and graze.
• rash – A temporary outbreak on the skin’s surface that is often reddish and itchy.
• receptor – A sensory nerve ending that responds to one of several stimuli, such as touch, temperature, light, taste, or pain.
• recurrence – A repeated occurrence; reappearance or repetition.
• recurrent – Happening again and again.
• reflex – An unconscious, automatic movement that occurs in response to sensory stimulation, for example the extension of the knee when the tendon below the knee is tapped.
• regenerative anemia – A form of anemia in which the bone marrow responds to the decreased number of red blood cells by increasing red blood cell production.
• regurgitate – To flow in the opposite direction than normal, as in backward flow of blood within the heart; to bring undigested food up from the esophagus (rather than the stomach) to the mouth.
• reinfestation – A reoccurrence of an infestation, as by fleas.
• reinforcement – Reward; any event that increases the chances that a certain behavior will be repeated.
• relapse – The return of an illness, especially after a period of apparent health or improvement.
• remission – A decrease in or a temporary disappearance of the signs of disease.
• renal – Of, relating to, or in the region of the kidneys.
• replicate – 
• reproduction – The process that gives rise to offspring.
• reproductive system – The organs involved in reproduction.
• reptile – Any of a class of air-breathing, usually ectothermic (cold-blooded), vertebrate animals, generally covered in scales or plates; examples include lizards, snakes, and turtles.
• resistance – An organism’s ability to keep from being affected by an infection; ability of a microorganism to withstand the effects of a previously effective drug or dosage.
• resistant – Having the capacity to withstand; relating to or conferring immunity.
• resorption – The process of reclaiming an established organ or structure in order to use its nutrients.
• respiratory – Of, relating to, used in, or affecting respiration (breathing).
• respiratory failure – Inadequate gas exchange or airflow in the respiratory system.
• respiratory sinus arrhythmia – The small variations in heart rate in healthy, quiet animals that are caused by pressure changes in the chest associated with breathing.
• respiratory system – The organs responsible for breathing, including the lungs, trachea, mouth, nose, and throat.
• respiratory tract – The passages through which air enters and leaves the body.
• reticulocyte – An immature red blood cell.
• retina – The rear inner surface of the eye, responsible for picking up light and transmitting it to the brain as visual signals via the optic nerve.
• retrovirus – Any of a family of viruses that store their genetic material as single-stranded RNA rather than 2-stranded DNA.
• reverse osmosis – Purification process by which water is forced through an extremely fine membrane and a carbon filter to remove even more compounds than are removed during normal filtration.
• rhabdomyolysis (sporadic exertional) – Severe cramping and stiffness of muscles following heavy exercise, leading to disintegration of muscle fibers; also called tying up.
• rhinitis – Inflammation of the nose.
• rhinosporidiosis – A chronic, nonfatal, fungal infection, primarily of the lining of the nasal passages and, occasionally, of the skin.
• rickets – A nutritional disorder of young animals caused by a lack of phosphorus or vitamin D, leading to malformation of bones and lameness.
• rickettsiae – A group of small bacteria that can live only within cells and that cause several diseases, including Rocky Mountain spotted fever, in animals and people.
• ringtail – A ring-like constriction of the tail, affecting mice, rats, or hamsters, caused by low humidity and high temperatures, and eventually causing gangrene and loss or partial loss of the tail.
• ringworm – A fungal skin infection affecting many animals and humans; dermatophytosis.
• RNA – Ribonucleic acid; a nucleic acid found in all living cells essential for the manufacture of proteins and carrying genetic information.
• Rocky Mountain spotted fever – An infection of humans, dogs, and other animals that is caused by Rickettsia rickettsiibacteria, transmitted by ticks.
• rodenticide – A compound used to poison rodents.
• root canal – The central cavity of a tooth that extends down into the roots of the tooth.
• Rotavirus – A genus of viruses that cause intestinal infection in young animals of several species, including birds and pigs.
• roughage – Another term for fiber, which aids digestion.
• roundworm – See
• ruminant – Any of various hoofed, even-toed, mammals such as cattle, sheep, goats, and deer, characteristically having a 4‑compartment stomach and chewing a cud consisting of partially digested food.

S

• saline – A solution of salt (sodium chloride) and purified water that has the same concentration of salts as the bloodstream.
• saliva – The clear liquid containing digestive enzymes and immune cells that is secreted into the mouth by the salivary glands.
• salmon poisoning disease – An infectious disease in which the infective agent is transmitted through the various life cycle stages of a flatworm known as a fluke. SeeElokomin fluke fever.
• salmonellosis – Infection with Salmonellabacteria, most often characterized by gastrointestinal signs such as diarrhea.
• sanitation – Measures and actions to maintain health through good hygiene.
• sarcocystosis – Disease in which the muscles and other soft tissues are invaded by intermediate life stages of single-celled organisms of the genus
• sarcoid (equine) – Fibrous tumor masses that resemble large warts. They commonly occur on the lower legs of horses.
• sarcoma – A malignant tumor formed in connective tissue, bone, cartilage, or certain types of muscle.
• scabies – Infestation by mites of the genus -Sarcoptes, which affect dogs, cats, horses, pigs, and other species; sarcoptic mange.
• scar tissue – The pale, inflexible connective tissue that forms at the site of an injury.
• scintigraphy – Seenuclear scintigraphy.
• sclera – The white outer coating that covers the eyeball, except for the central round area covered by the transparent cornea.
• scoliosis – A congenital sideways curvature or deformation of the spine.
• scraping – Cellular material obtained for examination by scratching a specific tissue with a clinical instrument.
• screwworm – The larval stage of certain disease-spreading flies.
• scrotum – The external pouch of skin and muscle containing the testes in male mammals.
• scurvy – A nutritional disorder caused by a lack of vitamin C and characterized by bleeding of the skin and mucous membranes, tooth loss, weakness, and spongy gums.
• scute – An external bony or horny plate or scale covering the skin of some reptiles, such as the shell of a turtle.
• sebaceous gland – A skin gland that secretes the oil known as sebum into the hair follicles and onto the skin.
• seborrhea – A disease of the sebaceous glands characterized by excessive secretion of sebum or an alteration in its quality, resulting in an oily coating, crusts, or scales on the skin.
• sebum – Oily secretion from the sebaceous gland that helps lubricate the skin.
• secondary hyperparathyroidism – The excessive secretion of parathyroid hormone by the parathyroid glands in response to hypocalcemia (low blood calcium levels).
• secretion – The process of secreting (generating) a substance from cells, or bodily fluids such as saliva, mucus, or tears.
• sedate – To administer sedatives, bringing about a relaxed state.
• sedative – A drug or other agent that induces sedation, a state of calm, restfulness, or drowsiness.
• sedentary – An adjective used to describe an animal or human that exercises little.
• seizure – Any of several types of interruption in normal bodily control or thought processes, often characterized by uncontrollable stiffness or jerking of the body, face, or limbs.
• semen – The viscous, whitish fluid containing sperm and seminal fluid that a male ejaculates during breeding.
• semiaquatic – An animal that frequents water but does not completely live in it.
• semilunar valves – Valves between the heart and the aorta, and between the heart and the pulmonary artery.
• sensory – Of or relating to sensations of pain, position, touch, temperature, taste, hearing, vision, and smell.
• sepsis – Illness resulting from the persistent presence of microorganisms or their toxins in the bloodstream. Also called septicemia or blood poisoning.
• septal defect – A hole in the membrane, or muscle wall, dividing the chambers of the heart.
• septic shock – A life-threatening condition caused by an infection in the bloodstream in which blood pressure falls dangerously low and many organs malfunction because of inadequate blood flow. See
• septicemia – See
• septicemic cutaneous ulcerative disease (SCUD) – A bacterial disease in turtles in which the scales are pitted.
• serotype – A group of related microorganisms that are neutralized by the same antibodies.
• service animal – Companion animal that is trained to help a person with disabilities, aid law enforcement personnel, help search for lost people, or other tasks.
• sheath – An enveloping tubular structure, such as the tissue that encloses a muscle or nerve fiber.
• shock – A condition of sudden failure of the circulatory system, brought on by excessive blood loss, severe infection, or nervous system dysfunction, among other causes.
• sign – Indication or evidence of disease, for example weakness, coughing, or diarrhea.
• silage – Animal feed made by storing green plant material, as in a silo.
• sinoatrial node – The heart’s natural pacemaker, which generates rhythmic impulses that cause contractions of the muscle fibers of the heart.
• sinus (cardiology) – A dilated channel or receptacle containing chiefly venous blood.
• sinus (respiratory system) – Any of several bony cavities in the head connected to the nasal cavity.
• sinus arrest – A pause or cessation of cardiac sinus pacemaker activity.
• sinusitis – Inflammation of the lining of the sinuses in the head.
• skeletal disorder – Disease affecting the development or structure of the bones.
• skin appendage – A small or secondary attachment to the skin, such as hair follicles, oil and sweat glands, and claws.
• skin tenting – Condition that occurs when a small section of skin is pinched away from the body does not snap back to its original position. It can be used to indicate the degree of dehydration of an animal.
• small intestine – The long, narrow part of the digestive tract that lies between the stomach and the colon.
• smear – A medical screening or diagnostic procedure in which a sample of cells (blood, for example) is collected and spread on a microscope slide for examination.
• soft tissue – Any of the body tissues other than bone and cartilage.
• solution – A drug dosage form that is dissolved in liquid, usually water.
• solvent – A substance in which other substances are dissolved to create a solution.
• somatostatin – A hormone produced chiefly by the hypothalamus that inhibits the secretion of growth hormone and various other hormones.
• soundness – Freedom from injury, disease, or illness; without damage.
• spasm – A sudden, involuntary contraction of a muscle or group of muscles.
• spawning – The process by which some animals, such as certain fish, reproduce.
• spay – To remove the internal reproductive organs (ovaries, uterus) of a female animal in order to prevent reproduction.
• species – A subdivision of a basic biological group, the genus, containing individuals that resemble one another and that may interbreed.
• spina bifida – A congenital defect in which the spinal column is imperfectly closed.
• spinal – Of, relating to, or situated near the spine or spinal cord.
• spinal cord – The long bundle of nerve tissue that runs from the brain to the end of the spinal column and connects to the majority of the peripheral nerves.
• spine – The backbone of a vertebrate.
• spirurid – A worm, transmitted by mosquitoes or ticks, that may cause skin sores or infect the stomach lining, body cavity, or blood vessels.
• splay leg – A leg or pelvic socket deformity causing the legs to spread out (splay).
• spleen – A glandlike, lymphoid organ that is part of the immune system and that stores blood cells and produces some types of white blood cells.
• splint – A rigid device used to prevent motion of a joint or of the ends of a fractured bone.
• sporadic – Happening or appearing at irregular intervals.
• spore – A reproductive cell, produced by bacteria or fungi, capable of developing into a new individual without fusing with another reproductive cell.
• sporocyst – The first sac-like reproductive stage in many parasitic flatworms that buds off cells.
• sporotrichosis – An infectious disease caused by a yeast-like organism that affects many species, including humans, and that often takes the form of localized, ulcerated skin sores.
• spot-on – A solution of active ingredients for application to the skin which typically contains a cosolvent and a spreading agent to ensure that the product is distributed to the entire body.
• squamous – Referring to the portion of the epithelium (skin) composed of flat, plate-like cells.
• squamous cell carcinoma – A form of skin cancer that usually originates in sun-damaged areas.
• stamina – 
• star-gazing – A sign of neurologic disease in which the neck is twisted backward and the animal appears to be looking up into the sky.
• stenosis – A constriction or narrowing of a duct or passage; an obstruction.
• stereotypic behavior – Repetitious, relatively unvaried actions that have no obvious purpose or function.
• stethoscope – An instrument used to magnify sounds produced within the body in order to determine health or diagnose disease.
• stifle joint – Knee joint; the tendons, ligaments, and other tissues that connect the upper and lower long bones of the rear leg.
• stillbirth – Unintentional death of the fetus in the uterus.
• stimulant – A drug or other agent that produces an increase in function of an organ or body part.
• stimulation – To cause physical reaction in something such as a nerve or organ.
• stimulus – An agent or condition that elicits a reaction or response from an organism.
• stomatitis – Inflammation of the mouth.
• strain – A group of organisms of the same species, having distinctive characteristics but not usually considered a separate breed or variety.
• strike – Maggot infestation, or myiasis.
• stunting – A reduction in overall growth or progress.
• stye – An infection of one or more of the glands at the edge of the eyelid or under it.
• subcutaneous – Located just beneath the skin.
• subcutis – The innermost of the 3 layers of the skin.
• subspectacle abscessation – A common bacterial eye infection in snakes.
• substrate – Ground covering such as newsprint, sand, peat moss, potting soil, wood shavings, or cypress mulch that are used to cover the bottom of cages for animals such as rodents or reptiles.
• subvalvular – Located below one of the heart valves.
• superficial – Located at the surface, or only affecting the surface.
• superficial flexor tendon – A tendon that flexes the joints of the lower leg.
• supplement – Something added to complete a thing, make up for a deficiency, or extend or strengthen the whole.
• supportive care – A wide range of nonspecific treatments for sick or injured animals designed to relieve the signs of illness and that may include injectable fluids, supplemental feeding, heat, or removal of stress.
• suppression – The reduction or stoppage of a normal bodily function.
• supravalvular – Located above one of the heart valves.
• surgery – Medical procedure to treat injury or disease involving an operation, such as removal or replacement of a diseased organ or tissue.
• susceptibility – The likelihood of being affected or infected; vulnerability.
• suspension – A dispersion of insoluble or poorly soluble drug particles in a liquid.
• suspensory ligament – A ligament that provides support for the fetlock joint in horses.
• suture – Any of the fine threads of specialized material used surgically to close a wound or join tissues; also the act of surgically closing a wound or joining tissues using a stitch or stitches.
• syndrome – A group of signs that occur together and signal a particular abnormal condition.
• synostosis – An abnormality in which 2 adjacent bones, such as vertebrae, fuse together.
• synovial fluid – Fluid contained within a joint cavity that helps lubricate the joint.
• synovial membrane – Membrane surrounding a joint between bones.
• systemic – A disease or condition that affects or spreads throughout the entire body rather than being confined to a single location. Also called generalized.
• systole – The second half of the heartbeat, characterized by the sound of the aortic and pulmonary valves closing, when the ventricles contract.

T

• T
• T cell – A type of white blood cell that participates in immune responses to infections and other diseases.
• T3, T4 – Two iodine-containing hormones produced by the thyroid gland that act on many cellular processes to regulate metabolic rate.
• tablet – A solid pellet made up of one or more compressed powdered drugs and perhaps fillers to be taken by mouth.
• tachycardia – A rapid heartbeat.
• tarsal joint – The hock, or ankle joint of the lower rear leg.
• tarsal – Of, relating to, or situated near the bones of the ankle.
• tartar – A hard deposit of organic material that forms on teeth.
• temperate – Mild or restrained in behavior or attitude. As refers to climate, neither very hot nor very cold.
• tendinitis – Inflammation of a tendon.
• tendon – An inelastic band of tough fibrous connective tissue attaching a muscle to a bone or other part.
• tension pneumothorax – A buildup of air in the space between the lungs and the chest wall; can lead to collapse of a lung.
• tentative diagnosis – Early, most likely diagnosis based on the history, physical examination, and signs of a disorder.
• teratogen – Agents or factors that cause or increase the incidence of a congenital defect.
• terrestrial – Living on the ground or underneath its surface.
• testes – The reproductive organs in a male vertebrate, which produce sperm and the hormone testosterone.
• tetanus – An often-fatal disease characterized by spastic contraction of muscles and caused by a toxin produced by Clostridium tetani Also called lockjaw.
• tetany – Continuous, spastic contraction of muscles, causing rigidity of limbs.
• tetralogy of Fallot – A complex congenital heart defect that produces a bluish tinge to skin and membranes caused by insufficient oxygen in the blood.
• therapy – Treatment for an illness.
• thermography – An imaging technique that records the heat emitted by bodies as infrared radiation; used to diagnose musculoskeletal disorders.
• third eyelid – Seenictitating membrane.
• third phalanx – The outermost bone of a finger or toe.
• thoracentesis – Procedure in which a needle is inserted into the chest cavity to withdraw excess fluid.
• thoracic – Of, relating to, or situated in or near the chest (thorax).
• thorax – The chest cavity, encased by the ribs and containing the heart, lungs, and other organs.
• thrombocyte – See
• thrombopoietin – A hormone that regulates the production of blood platelets.
• thrombosis – Obstruction of an artery by a blood clot.
• thrombus – A blood clot formed in an artery or vein, frequently causing blockage of the blood vessel.
• thymus – A gland in the upper chest or the base of the neck that is the site of maturation of some types of lymphocytes, a class of white blood cell.
• thyroid gland – An endocrine organ in the base of the neck that regulates metabolism.
• thyroid hyperplasia – Enlargement of the thyroid gland. Also known as goiter.
• tick – Parasitic invertebrates with 8 legs that suck blood and can transmit several diseases.
• tick fever – SeeRocky Mountain spotted fever.
• tissue – Interconnected cells that perform a similar function within an organism.
• tonometer – A device for measuring pressure, particularly pressure inside the eye.
• tonsillitis – Inflammation of the tonsils.
• tonsil – A small mass of lymphoid tissue in the throat.
• topical – Involving local application to a part of the body, especially on the skin; for instance, a topical ointment.
• torpor – A state of deep unconsciousness, usually brought on as a result of environmental conditions such as low temperature.
• torticollis – A twisting of the neck to one side, resulting in the head being tilted; can be caused by an ear infection or neurologic disease. Also called wry neck.
• toxemia – A condition brought on by toxins in the blood, especially those produced by bacteria or a metabolic disturbance.
• toxic – Containing or being a toxin; poisonous.
• toxicant – A toxic substance.
• toxicity – The degree to which something is poisonous.
• toxicology – The branch of science that studies how poisons affect animals and people and how they respond to poisons.
• toxicosis – Disease or condition resulting from poisoning.
• toxin – A poisonous material; most often used to describe poisons produced by plants, animals (such as venomous snakes), and some bacteria.
• toxoid – A substance that has been treated to destroy its toxic properties but retains the capacity to stimulate production of antibodies that can neutralize the original toxin.
• toxoplasmosis – Infection by Toxoplasmamicroorganisms, which can cause serious damage to the central nervous system, especially in young animals.
• trachea – The thin-walled, cartilaginous tube that connects the throat to the lungs. Also called the windpipe.
• tracheal intubation – Insertion of a tube into the trachea to help an animal breathe or to administer anesthesia.
• tracheobronchitis – Inflammation of the trachea and large airways (bronchi).
• tracheostomy – An emergency procedure for inserting a tube through the neck into the trachea to allow breathing.
• tranquilizer – Any of a class of drugs used to produce a calming or soothing effect.
• transdermal – Describes a medication delivery form that is absorbed through the skin into the bloodstream, such as a patch or an ointment.
• transformation – The 2-step process of development of cancerous cells from healthy cells, consisting of initiation and promotion.
• transfusion – The transfer of whole blood or blood products, such as packed red blood cells, from one individual to another.
• transmission – The passing of an infection from one individual to another.
• trauma – Damage to living tissue caused by an outside source; a wound.
• trematodes – Parasitic flatworms.
• treponematosis – Infection by bacteria of the genus Treponema, which includes syphilis.
• trichinellosis – A parasitic disease caused by a type of roundworm, transmittable to humans and often associated with eating undercooked pork. Also called trichinosis.
• tricuspid valve – The valve between the right chambers of the heart, through which blood flows from the right atrium to the right ventricle.
• trocarization – A technique used to relieve the pressure in the abdomen when it becomes distended with gas due to an intestinal blockage.
• tube feeding – Delivery of nutrients, either a special liquid formula or pureed food, through a tube advanced through the nose or mouth into the stomach.
• tuberculosis – Disease of many animal species and humans caused by infection with bacteria of the genus Mycobacterium, which typically affects the respiratory system.
• tularemia – A highly contagious bacterial infection found especially in wild rabbits and rodents that may also affect humans, and which may be transmitted by ticks or direct contact with an infected animal.
• tumor – An abnormal, usually well defined, mass of tissue within an animal; can be either malignant (cancerous) or benign.
• tympanic bullae – The round bones behind the ears.
• Tyzzer’s disease – A common infection of rabbits and rodents, caused by Clostridium piliformebacteria, that typically affects the digestive system. Other species are occasionally affected.

U

• ubiquitous – Existing everywhere.
• udder – Another term for the mammary glands of farm animals, including cows, pigs, and horses.
• ulcer – A sore of the skin or of a mucous membrane (for instance, the mouth or stomach lining) characterized by erosion and loss of surface tissue.
• ulcerate – To develop an ulcer.
• ulcerative dermatitis – A skin disorder characterized by formation of ulcers in multiple locations; can be a result of itching and scratching caused by another condition.
• ulna – One of the 2 long bones of the lower part of the front leg.
• ultrasonography – A diagnostic test that uses a machine which emits ultrasonic sound waves, or sounds above the range that humans can hear, to produce a 2-dimensional image of the inside of a body cavity.
• ultraviolet (UV) radiation – Light energy radiating from the sun that is not visible to the human eye and that can cause sunburn and increase the risk of skin cancer.
• umbilical – Related to or situated in the umbilical cord, the navel, or the area surrounding the navel.
• umbilical cord – The flexible tube connecting the fetus to the placenta, through which nutrients are delivered and waste is expelled.
• unconscious – Lacking awareness and the capacity for sensory perception; not conscious.
• unthriftiness – Failure of a young animal to grow or gain weight at a normal rate in spite of an adequate diet and absence of obvious illness.
• upper airways – The portion of the respiratory tract that extends from the nostrils or mouth through the throat (pharynx).
• urate – A salt formed from uric acid. Seeuric acid.
• uremia – A buildup of toxic chemicals in the blood that occurs when the kidneys are not functioning properly.
• ureter – The narrow tube that connects the kidney to the bladder.
• urethra – The tube from the urinary bladder through which urine exits the body.
• uric acid – A weak acid present in the urine, which can lead to gout or other disorders in birds if it builds up to high levels.
• urinalysis – Laboratory analysis of urine, used to aid in the diagnosis of disease.
• urinate – To expel liquid waste from the body by contracting the urinary bladder.
• urine scalding – Skin inflammation caused by prolonged contact with urine.
• urogenital tract – Relating to or involving the organs of the urinary tract and the reproductive system.
• urolith – A buildup of mineral salts in any part of the urinary tract; also called a urinary calculus or stone.
• urolithiasis – A condition brought on by the formation of stones (calculi) in the urinary system of an animal.
• urticaria – See
• uterus – The organ of the female reproductive system in which the fetus develops.
• uvea – The middle layer of the eye, which includes the iris and the muscles that control it.
• uveitis – Inflammation of the uvea.

V

• vaccination – The administration of a substance to produce immunity against a specific disease; immunization.
• vaccine – A product, including dead or weakened forms of an infectious agent or molecules that are part of the agent, that prompts the immune system to develop defenses against that specific organism.
• vagina – The lubricated muscular tube of female mammals that connects the cervix to the vulva, forming the external opening of the genitals.
• valve – A membranous structure that closes to prevent the backward flow of material through a canal or passage.
• valvular disease – Disease resulting in failure of the heart valves to open or close properly.
• vascular – Of, characterized by, or containing vessels that carry fluids, such as blood or lymph, through the body of an animal.
• vascular network – The collection of vessels that carry or circulate bodily fluids.
• vasculitis – Inflammation of the blood vessels.
• vasodilator – Any of a class of drugs intended to lower blood pressure by widening blood vessels, thus increasing blood flow.
• vector – An organism, such as a tick or mosquito, that carries an infectious agent between susceptible animals. A vector may also be mechanical (nonliving), such as clothing or equipment.
• vein – Any of the system of blood vessels that carry blood toward the heart.
• venae cavae – The 2 largest veins, which return blood from the body to the right atrium.
• venereal disease – A contagious disease typically spread through sexual activity.
• venom – A poisonous fluid injected by the bite or sting of an animal.
• venous dilator – A drug that dilates the veins coming to the heart and increases the amount of blood that enters the heart.
• ventricle – Either of the 2 lower chambers of the heart.
• ventricular fibrillation – A common arrhythmia of the heart characterized by chaotic, ineffective contraction of the heart muscle.
• vertebra – Any of the bones forming the spinal column.
• vertebrate – An animal with a backbone, such as fish, reptiles, mammals, and birds.
• vesicle – A small, raised area of skin, containing fluid; blister.
• vesicular stomatitis – An acute viral disease of horses and pigs, transmitted by mosquitoes and other insects and signaled by excessive drooling, loss of appetite due to mouth blisters, and lameness due to foot ulcers.
• vestibular system – The organs in the inner ear that control balance.
• veterinarian – An individual trained and licensed to treat the medical conditions of animals; a doctor of veterinary medicine.
• veterinary dermatologist – A veterinarian specializing in the treatment of skin disorders.
• veterinary family practice – Also known as “bond-centered practice,” in which the veterinarian establishes a lifelong relationship with families and their animals and cares not only for the medical welfare of the animal, but also for the social health of its family.
• vipers – A group of highly poisonous snakes whose long fangs fold back when not in use.
• viral – Of, relating to, or caused by a virus.
• virus – A tiny infectious agent consisting of a genetic material (RNA or DNA) in a protein coat, which relies on host cells to reproduce.
• visceral – Relating to or affecting one or more of the soft internal organs of the body, especially those within the abdominal cavity.
• visceral gout – An inflammatory buildup of uric acid metabolites in the internal organs of reptiles or birds, leading to pain and discomfort.
• visceral leishmaniasis – A chronic, severe disease of humans, dogs, and certain rodents caused by protozoa, characterized by skin lesions, lymph node enlargement, weight loss, anemia, lameness, and kidney failure.
• vitamin – Any of a group of compounds that are essential for proper body function and growth.
• vitamin D – A fat-soluble vitamin required for normal metabolism of calcium and phosphorus.
• volume overload – A form of heart failure that results in an increase in the size of the one or both ventricles, the lower chambers of the heart.
• vomit – To expel the contents of the stomach; to throw up.
• vulva – The external female reproductive organs.

W

• warm-blooded – An animal that maintains a relatively constant and warm body temperature independent of environmental temperature. Also called homeothermic.
• wart – A hard, rough lump growing on the skin.
• water mold – An aquatic fungus living chiefly in fresh water or moist soil.
• water salinity – A measure of the amount of salt in water.
• weaning – The process of getting an infant mammal adjusted to eating food rather than drinking its mother’s milk.
• wheal – A localized area of fluid buildup in the skin that may be pale or reddened and may itch; a hive.
• white blood cell – Any of a group of infection-fighting blood cells. See
• withers – The ridge between the shoulder blades of a horse.
• womb – Another word for uterus. See
• worms – Soft-bodied organisms, many of which are parasitic and infect animals and/or humans.

X

• x-ray – A high-energy form of electromagnetic radiation that can be used to produce images that allow a veterinarian to see inside the body; also used to describe the pictures produced by the rays, which are also called radiographs.
• x-ray therapy – Seeradiation therapy.

Y

• yeast – A small, single-celled fungus that ferments carbohydrates; some types can infect humans and animals.
• yellow fat disease – A condition in cats involving inflammation of the fatty tissue, thought to be due to an excess of unsaturated fatty acids in food combined with a deficiency of vitamin E.

Z

• zinc toxicity – A typically chronic form of poisoning caused by consumption of items containing the metal zinc and characterized by lameness and stiffness.
• zoonosis – A disease that can be passed from animals to people.
• zoonotic risk – The likelihood that a disease will be passed from an animal to people.
• zygomycosis – A fungal infection of the lining of the mouth, nasal passages, and tissue beneath the skin, or the sides of the head, neck, and body.

 

abiotic – devoid of life; the nonliving components of any environment.

abomasum – the final compartment of the ruminant stomach, also known as the fourth or true stomach of the cow, comparable in function to the simple-stomached animals.

abortion – expulsion of the fetus (or fetuses) by a pregnant female before the normal end of a pregnancy.

acetonemia (ketosis) – a metabolic disease characterized by high concentrations of ketone bodies (b-hydoroxybutyric-acid, acetoacetic acid and acetone) in blood or other body tissues.

acclimatization – adjustment to altered environmental conditions.

adaptation – process by which organism becomes adjusted to altered environment.

aflatoxin – toxin produced by the fungi Aspergillus flavus and Aspergillus parasiticus.

ADF – acid detergent fiber; an indicator of relative digestibility of forages

adipose – fatty

afterbirth – the fetal membranes that attach the fetus to the membranes of the pregnant female and which are normally expelled from the female within 3 to 6 h. after parturition.

agency boards – these boards require the product to be marketed through a board. Therefore, commodity board pays the producer and collects from the buyer to whom the product has been delivered. Some of these boards have the authority to set the price the producer receives.

agribusiness – a combination of the producing operations of a farm, the manufacture and distribution of farm equipment and supplies and the processing, storage and distribution of farm commodities.

agriculture – the science or art of cultivating the soil, producing crops and raising livestock and, in varying degrees, the preparation of these products for man’s use and disposal (i.e., marketing). A human activity involving the exploitation of selected animal or plant species to produce things people desire.

AI = artificial insemination – the technique that involves breeding of females without the males being physically present.

albumen – a viscous protein that comprises most of the white of eggs.

alleles – alternative forms of a gene at a specific locus; a location on a chromosome.

all-in all-out systems – a livestock management system in which all animals are introduced into an isolated confinement unit, taken through the appropriate stage of the production cycle and all moved out at the same time. The unit is then cleaned thoroughly and disinfected before a new group comes in.

ambient – that which surrounds.

amino acid – nitrogen containing component of a protein molecule

anabolic – tissue increasing.

analogue – a compound or product that is synthesized or manufactured to be similar to a naturally occurring substance.

anamnestic response – the result of immunological memory. If a previously sensitizing antigen is ever encountered again, antibody production is much quicker and usually in greater amounts than that observed following the initial encounter.

androgen – male sex hormones, associated with secondary sex characteristics.

annual consumption trends – the tabulation of the food products purchased and consumed on yearly basis by a certain population.

ante-mortem – before death.

anthelmintic – compound that kills or expels internal parasites.

antibiotic – chemical compounds from living cells, that inhibit growth or kill microorganisms.

antibody or immunoglobulin – a globulin protein produced by lymphocytes in response to antigenic stimulus. Antibodies bind to antigens and reduce the latter’s ability to disrupt body functions.

antigen – a substance, usually a protein molecule or cellular component, that is foreign to the body

and stimulates an immune reaction.

antimicrobial – substances used to inhibit the growth of molds, yeasts or bacteria eg. nitrites,

disinfectants, etc.

antioxidant – compounds that delay or slow the rate of oxidation of autoxidizable substances e.g. BHA, Vitamin E.

antiseptic – compound that kills or inhibits bacterial growth, particularly those agents applied to living tissue.

aquaculture – the production of fish.

atrophy – wasting away or decreasing in size of cells, organs or entire body; due to disuse, disease or severe malnutrition.

autonomic nervous system – portions of the nervous system that regulate cardiac, respiratory, glandular, renal and other activities usually under involuntary (autonomic)# rather than voluntary control.

avian – pertaining to poultry.

backfat – a measurement taken at the loin of a pig and used in calculating the final price of a pork carcass.

backgrounding – feeding cattle on pasture or roughage before finishing.

barrow – a castrated boar.

battery cage – a series of cages in which hens are confined for laying.

biological stimulus – a living organism that is capable of exciting a response in some other organism.

biological clock – mechanism that enables regulation of an animal’s physiological or behavioral activities to external cycles or rhythms.

biomagnification – the accumulation/magnification of a substance as it moves through the food

chain.

biomass – total weight of organic material present per unit of area or volume.

biotic – living things.

boar – uncastrated male pig

bovine – pertaining to cattle.

boxed beef (pork) – precut portions of beef or pork prepared by the meat processing plant for wholesale delivery.

breakers – eggs produced which, because they are in excess of consumer demand are bought by the Ontario Egg Producers’ Marketing Board and sold to the processing industry for use in products like noodles, mayonnaise and cake mixes.

breed – a group of animals descended from common ancestors and possessing similar characteristics.

BCA – breed-class-average, a number used in official Canadian recording systems to compare an individual’s production for milk, fat or protein with the national average.

breeder – a male or female kept for reproduction.

broilers – chickens raised for meat rather than egg-laying purposes.

broiler-breeders – mature broiler chickens kept for breeding.

buck – male goat.

bull – male member of the bovine species.

bullock – castrated bull, used for draft

butterfat – the lipid in milk.

calf – a young bovine animal, male or female, under one year of age.

calving – the process of a cow giving birth to a calf.

candled, candling – a method used in grading eggs in which the eggs are passed over a bright light so their contents can be inspected and any cracks or other irregularities detected.

capon – a castrated rooster.

caprine – pertaining to goats.

carcass – the dressed body of a meat animal.

carcinogen – a cancer causing agent.

carnivorous – feeding on animal tissues.

castrate – to remove the gonads of a male animal.

cecum (caecum) – a blind pouch at the beginning of the large intestine, prominent in horses and pigs.

cellulose – a prevalent polysaccharide in the fibrous portions of plants, digestible by microbial fermentation in the rumen, cecum or large intestine.

central nervous system – the brain and spinal cord.

cereal – edible grain.

cheddaring – a process that is unique to the production of cheddar cheese. Matted curd is cut into blocks which are turned at 15 minute intervals and piled on one another two or three deep. Allows acid formation and squeezes whey from the curd.

chemical stimulus – a chemical substance capable of exciting a response.

chevon – goat meat.

cholesterol – fat soluble essential nutrient required by the body as a part of all cell membranes and the synthesis of sex and adrenal hormones.

chromosomes – the rod or string like structures which contain the DNA in the nucleus of eukaryotes.

climatic (thermal) stimulus – changes in temperature or other weather related factors that cause a response.

clones – all of the offspring produced by budding, parthenogenesis or nuclear transfer. They are presumed to be genetically identical.

cock – male chicken.

cockerel – male chicken less than one year old.

colostrum – milk that is produced by the mother during the first few days after giving birth. This milk contains a high concentration of maternal antibodies to provide offspring with temporary protection against infectious diseases.

comfort zone – the thermoneutral zone or temperature range in which animals maintain their body temperature within the thermal range without expending any extra energy.

commodity price – the price or value of an agricultural product.

concentrate – a high quality, low fiber feedstuff, including cereals and milling by-products.

concentration – reduction of water content and corresponding increase in solids content for a preservative effect on foods. Also decreases product volume and weight.

conception – fertilization or union of oocyte and spermatozoon.

conceptus – product of fertilization, formed through the union of spermatozoon and oocyte, with the potential to develop through embryonic and fetal stages into a viable offspring.

condition – refers to the amount of flesh (body weight), quality of hair coat, and general health of animals.

conduction – the direct movement or transfer of heat from warmer to cooler objects that are in contact with each other.

consumer – one that utilizes economic goods, a buyer of products.

corn silage – a feedstuff consisting of fermented whole corn plants (corn cobs and plant matter).

cost of production formula – (i.e., Ontario Egg Producers’ Marketing Board) – the national formula used to determine the farm gate price of one dozen Grade A large eggs by taking into account all the average costs incurred by an egg producer in the production of those eggs.

convection – involves heat exchange through a physical medium such as air or water. A temperature gradient occurs from the warmer body surface through the medium to the surrounding environment.

cow – mature bovine female.

creep – an enclosure into which young (small) animals may enter but larger animals cannot. Any feeders in this area or in farrowing crates or parturition pen that are only accessible to the young are called creep feeders.

crutching – to remove wool from around the perineal and inguinal areas of sheep to prevent soiling and to provide access to teats

cut – to castrate.

depreciation– to lower the price or estimated value, or of less value than usually assigned.

depressed prices – lower prices than average for a commodity usually due to economic depression.

diet – the ingredients or mixture of feeds provided for an animal.

disinfectant – compound that kills or inhibits bacterial growth, particularly applied to agents that are used on inanimate objects.

disposable income – the amount of money remaining to a consumer after deduction of taxes.

distress – excessive stress that causes anxiety, fear or pain.

distributor – one that markets a commodity. It may be as a wholesaler or retailer.

docking – removal of the tail. A common practice in lambs

doe – female goat.

dry – an animal capable of lactating that is no longer producing milk.

Dutch auction – a public sale in which the prices of an object or article is decreased electronically until the first bidder offers to buy. Prices are flashed on the board and the bidder (buyer) pushes a button to indicate his intention to buy.

ecosystem – an interacting community of biotic organisms including their physical environment.ectotherms – animals whose body temperature fluctuates with ambient temperature.

edible oil – an oil product, i.e., corn oil, canola oil, sunflower oil, soybean, peanut, beef, pork and olive oil that is used in the preparation or cooking of food.

egg grading station – a facility licensed by Agriculture Canada where producers bring their eggs to be graded. They must collect the levies on all eggs purchased and remit them to the Ontario Egg Producers’ Marketing Board.

elastrator – an instrument for use in stretching a specially made rubber ring, which may be used in dehorning cattle as well as in castrating cattle and sheep.

electronic bidding – using electronic means, a buyer indicates his intention to buy. The buyer therefore does not have to be present at the auction.

embryonic mortality – loss of conceptus in first few weeks or months of gestation.

endosperm – main portion of a cereal kernel (85% by wt) consisting mainly of starch and protein. Recovered and pulverized in the milling process to yield flour.

endotherms – animals that maintain stable body temperatures.

enrichment – addition of specified amounts of selected nutrients in accordance with a standard identity as defined by the Food and Drugs Act.

environment – the sum total of all external conditions affecting well-being and performance.

environmental contaminant – a compound present in soil, water or air.

essential amino acids – amino acids required by animals but not synthesized by them.

estrus – period of time when the female will allow mating.

ET = embryo transfer – technique of harvesting embryos from one female and placing them into other females to complete gestation.

evaporation – heat loss resulting from the latent heat of vaporization which removes heat from a wetted surface.

evisceration – removal of the internal organs; performed after an animal has been slaughtered.

ewe – mature female sheep.

exsanguination – removal of blood; performed after an animal has been slaughtered.

farmer – a person who cultivates the land to grow crops or raise livestock for food production.

farmgate sales – the direct sale of a product from the farmer to the consumer, without going through a marketing board or grocery store.

farrowing – the process of a sow giving birth to piglets.

farrowing crate – a small enclosure for confining a sow and her litter in such a way that the sow may farrow normally, without hazard to the newborn pigs, and which provides them with space of their own on either side of the sow’s compartment.

fertile land – land that has good soil composition for the growing of agricultural products, capable ofsustaining abundant plant growth.

fecundity – efficiency of an individual in production of young. Animals that bring forth young frequently, regularly, and, in case of those that bear more than one offspring at a birth, in large numbers, are said to be fecund.

fertility – the ability to produce offspring.

fetus – the unborn young in the later stages of development.

filly – a young female horse.

fingerling – smaller fish, usually applied to trout of about 50 – 100 gm in weight or 16- 20 cm in fork length.

first buyer the first purchase of a commodity by a processor, marketing board, retailer or consumer when the product leaves the farm.

fluctuating market – an uncertain shift up and down of demands for agricultural products, the levels of productions and the costs for those products.

fluid milk – milk used in the manufacture of pasteurized fluid milk and cream.

foal – a young horse

foaling – the act of giving birth to a foal

Food and Drugs Act – consumer oriented legislation passed in 1953 designed to protect Canadians in the use and consumption of food and drugs, cosmetics and medical devices.

food processors – a person or company that slaughters and/or processes agricultural commodities for retail use.

food system – the production, processing, transportation, distribution and preparation of food.

fortification – addition of nutrients to a food to render it a good to superior source of the added nutrients. May include nutrients not normally associated with the food.

free stall – a housing system for dairy cattle in which the barn is constructed with a series of stalls (one per cow) and in which the cow can choose in which stall she wishes to rest.

freshen – a cow giving birth to a calf.

fry – newly hatched fish larva still with its yolk sac attached.

galactopoiesis – stimulating milk production.

gelding – a castrated male horse.

gene – the particular nucleotide sequence of a chromosome segment which influences development of a specific characteristic.

genotype – the specific genetic material on the chromosomes of an individual.

germ – the embryo of a cereal kernel.

gestation – pregnancy.

gestation crate – a stall for housing an individual sow or gilt during pregnancy.

gilt – female pig, prior to first calving.

graded – to assign, through an inspection process, grades which indicate the standard of food quality.

grower fish – fish past the fingerling stage, growing up to market weight.

harvest – the season for gathering in agricultural crops, to gather in a crop by mechanical or manualmeans.

hay – whole forage plants which are cut and dried for animal feed.

haylage – forage ensiled at relatively low moisture content (usually 40 to 50 %).

heat – see estrus.

heifer – female cow, prior to the first calving.

helminths – parasitic worms

herbivorous – feeding on plant tissues.

heterozygosity (heterogeneous) – an organism possessing dissimilar alleles of a particular trait.

heritability – the proportion of total variability among animals due to genotype.

heterosis – see hybrid-vigour.

high moisture grain – cereal grain (most commonly corn) stored in silos at moisture content of 22 to 40%.

homeotherms – animals that maintain a stable body temperature.

homeostasis – maintaining stable internal body conditions.

homogenization – mechanical treatment of milk which breaks large fat globules into many small ones. The resulting small fat globules remain dispersed in the milk and do not migrate to the top of the container to form a cream layer.

homozygosity (homogeneous) – an organism possessing similar genes (alleles) for a trait.

hormone – a chemical messenger secreted by ductless glands in the body and which exerts a profound effect on physiological function. Examples are thyroxin, estrogen, cortisone,, etc.

hybrid-vigor (heterosis) – offspring performance greater than average of parents.

hyperplasia – growth by increase in cell numbers.

hypertrophy – growth by increase in cell size.

immunity – developing resistance to a specific pathogenic microorganism.

implant – an object or material inserted into the body tissue (usually beneath the skin of domesticated animals).

import quota – a limit or restriction on the amount of a product which can be brought into Canada

from another country, imposed to prevent dumping (goods sold in Canada at a price lower than that in the country of origin) or to support a national supply management program.

in-calf – pregnant cow.

index – a value assigned to a pork carcass based on the weight of the carcass and the thickness of the backfat. A high index predicts high yield of meat from the carcass. The price paid to the farmer increases as the index value increases.

industrial milk – milk used in the manufacture of milk products, such as cheese, evaporated and dried milk products, butter, ice cream and yogurt. Also referred to as manufacturing milk.

infection – entry of pathogenic microorganisms into the body.

inflammation – tissue reaction to injury or infection, characterized by heat, redness, swelling and pain.

initial sale – the first sale of a farm product. The initial sale of livestock is usually made to the packer. Fruits and vegetables are sold initially to a processor, a wholesaler or, occasionally, directly to the consumer.

in-lamb – pregnant ewe.

in-pig – pregnant sow.

inputs – products used by the farmer to produce livestock or a crop, i.e., fertilizer, pesticides, seed, animal feed, fuel.

involution – a decline in size or activity of tissues and/or organs. For example, the mammary gland tissues normally involute with advancing lactation. The uterus involutes within a few days or weeks after a female gives birth to young.

ketosis – a metabolic disease (also called acetonemia) characterized by high concentrations of ketone bodies (b-hydoroxybutyric-acid, acetoacetic acid and acetone) in blood or other body tissues.

kid – young goat.

kidding – doe giving birth to kid.

lactation – production of milk.

lamb – young sheep.

lambing – a ewe giving birth to a lamb.

layer – a hen which is kept specifically for the production of eggs. Most layers in Ontario are WhiteLeghorns.

legislation – rules or laws passed by Parliament. The Parliament of Ontario has given the Ontario Farm Products Marketing Board power to monitor the action of all the commodity marketingboards in the province.

leucocyte (leukocyte) – usually referring to white blood cells.

levy – a fee paid by each producer for each dozen eggs sold. These fees finance the administration of the Ontario Egg Producers’ Marketing Board and the Canadian Egg Marketing Agency, aswell as the promotion of eggs and egg products.

lower critical temperature (LTC) – the temperature at which an animal must begin to expend energy to prevent a decrease in body temperature.

manufacturing milk – see industrial milk.

mare – a sexually mature female horse.

market conditions – the state of the prices paid to farmers for their products. If market conditions are stable for a specific product the, price paid for that product is not changing drastically from day to day.

marketing – selling farm products to the processor, wholesaler or consumer.

marketing board – a group of people elected to represent the producers of a specific product and to devise a plan for selling the product.

marketing plan – a system for selling a specific agricultural product.

marketplace – the buyers of a product and the price they are willing to pay.

market price – the amount that a buyer will pay for a specific product on a given day.

market service charge – as an example the fee paid by the hog farmer to the Ontario Pork Producers’ Marketing Board for each hog sold. This pays for the operation of the market yards, selling, settlement, organization, research and product promotion.

market yard – the location to which a farmer ships his hogs when they are ready for market. There are many market yards in Ontario operated by the Ontario Pork Producers’ Marketing Board.Most Ontario hogs must be sold through these yards.

mastitis – inflammation of the mammary gland.

metritis – an inflammation of the uterus

milk fever – substantial reduction in plasma calcium which interferes with nerve transmission, causing partial or almost total paralysis occurring at or just giving birth and initiation of lactation.

monogastric – animal with a single compartment stomach.

mycotoxin – toxic compounds, produced by fungi, that contaminate plants.

negotiating board – represents the farms in dealings with the initial buyers of a farm product. The buyers and the board must agree on a minimum price and on the terms of sale (quality and amount of produce).

offshore supplies – quantity of a product that countries outside Canada have produced.

omasum – the third compartment of the ruminant stomach, also known as the third stomach. It has a book-leafed appearance and is the site of water absorption from the digesta.

omnivorous – feeding on both animal and plant tissues.

Ontario Farm Products Marketing Act – given power under the Farm Products Marketing Act to oversee the provisions of the Act, Regulations or any Marketing Plan. Plans reviewed by the Board may apply to one or more farm products or to person engaged in the production and marketing of the regulated product, and may be limited to one or more areas in Ontario.

oocyte – female gamete or egg.

open – not pregnant.

output – quantity of product available for sale to marketplace.

ovary – primary female reproductive organ.

overhead – operating expenses of the farm excluding labour and materials. Taxes, utilities, rent or mortgage payments are overhead expenses.

ovine – pertaining to sheep.

packing plants – a meat processing factory. Cattle, sheep and hogs are shipped to a packing plant where they are slaughtered, inspected by government inspectors and prepared for wholesale or retail distribution.

palatability – refers to the avidity with which an animal selects a component from among several different feed choices.

pale-soft-exudative (PSE) pork – pork that is soft, pale and loose-textured with little or no marbling.

parous – females that have produced young.

parturient paresis – substantial reduction in plasma calcium which interferes with nerve transmission, causing partial or almost total paralysis occurring at or just giving birth and initiation of lactation.

parturition – the act of giving birth to offspring.

pasteurization – a heat process designed to destroy food pathogens and most food spoilage organisms but not to sterilize the product.

pathogenic – able to cause disease

pathological – pertaining to pathology

pathology – structural and functional manifestation of disease

performance test – merit testing of individual animals, usually for rate of weight gain, feed efficiency, milk production, or other performance trait.

phenotype – set of observable characteristics of individuals groups as determined by genotype and environment.

physical stimulus – some abiotic factor capable of producing a response, usually through pressure, friction or some other mechanical force.

pinch – castrate by crushing the spermatic cord.

placenta – the vascular structure by which the fetus is nourished in the uterus.

poikilotherms – animals whose body temperature fluctuates with external environmental temperature.

porcine – pertaining to pigs.

porcine stress syndrome (PSS) – a clinical syndrome characterized by rapid death of pigs after exposure to distress. Contributing factor in pale-soft-exudative (PSE) pork.

post mortem – after death.

postpartum – after birth.

prepartum – before birth.

price-setting board – an elected group of producer representatives. They regulate the selling price for a product and the amount of product which can be sold in Ontario. Sometimes called a Supply Management Board.

probiotic – living organisms used to manipulate fermentation in the rumen.

processor – the person or company that buys the farm-fresh products and prepares them for retail sale so that flavor and nutritional values are preserved. Canning, freezing, pickling and drying are a few processing methods.

production cycle – a sequence beginning with the mating of a mature female and progression through gestation, parturition and subsequent events in the life of both the dam and offspring.

production quota – a limit or restriction on the amount of a specific product that one farmer is allowed to produce for sale. Farmers buy or sell quota, the right to produce specified amount.

progeny – offspring.

progeny test – genetic evaluation based on performance of offspring.

prolificacy (fecundity) – the number of offspring actually produced by a female.

proteinaceous – containing protein.

provincial inspector – a person employed by the provincial government to ensure the wholesomeness of food products.

pullet -a young female chicken

raceway – long, narrow culture ponds with inlets and outlets at opposite ends so fish can grow in streams of controlled velocity.

radiation – the transfer of heat by electromagnetic waves passing between two separated objects without any heating of the intervening space between emitter and absorber.

ram – male sheep.

rancidity – the oxidation of fats.

ration – the 24h feed allowance for an animal.

rbST – recombinant bovine somatotropin (see somatotropin).

receivership – a loss of ownership of a business due to inability to pay back borrowed money. The receiver, usually a bank or other financial institution, takes possession of the business and often sells it to recover the money lent to the original owner.

ROP – Record of Performance, an Officially certified measure of production.

rennet – extracted from the fourth stomach of the calf, the enzyme component rennin is used to coagulate milk.

retailer – one who sells directly to the consumer.

reticulum – the second compartment of the ruminant stomach, also known as the second stomach. The lining has a honeycombed appearance to increase the surface are for absorption.

rigor mortis – the permanent contraction of skeletal muscle associated with death.

rooster – male chicken.

roughage – a high fiber feedstuff, usually low in energy and often utilized by ruminants.

rpST – recombinant porcine somatotropin (see somatotropin).

rumen – the first compartment of the ruminant stomach, also known as the first stomach. This is the site of fermentation of the consumed feed by microbes.

rumination – the process of regurgitation and re- chewing food from the rumen.

salmonellosis – illness resulting from infection by salmonella species of bacteria.

senescence – those processes that follow physiological maturity or horticultural maturity and lead todeath of tissue.

serve – to mate.

settle – to become pregnant or to conceive.

ship – transport goods from one location to another by road, rail, air or water.

shipping fever – respiratory disease usually accompanying transport.

silage – forage preserved by fermentation in a silo or under conditions that exclude air.

silo – a structure in which forage is preserved by fermentation under anaerobic conditions and subsequently stored until fed to livestock.

slatted (or slotted) floor – floor composed of solid slats with spaces or slots between to permit excretia to pass through, usually into a pit below.

somatotropin – growth hormone. A compound that can improve the milk yield of a cow or growth and carcass composition of a meat producing animal by repartitioning the nutrients. (i.e., rpST or rbST).

sow – mature porcine female.

SPF – (Specific Pathogen Free) – used to designate a herd or flock that is certified free from certain specific pathogenic organisms.

spermatozoa – male gametes.

stag – male deer or a boar castrated after maturity.

stallion – a sexually mature male horse.

steer – a castrated bull.

sterilization – the complete destruction of microorganisms.

stimulus – something initiating activity, see stress.

stoker – cattle fed lower levels of nutrients for a longer period of time, often on pasture.

stockyards – place where animals from different sources are assembled , usually for sale.

stress – any force or stimuli causing mental or physical response.

superovulation – release of more than the normal number of oocytes from the ovary.

supply management – regulations controlling the amount of a product which a farmer can produce for sale and the method of sale of the product.

swim-up fry – fry that have absorbed their yolk sac and are ready to consume feed.

table eggs – eggs which are sold directly to the consumer, either through retail stores or in restaurants.

teaser – a vasectomized or otherwise altered male that cannot fertilize but may stimulate estrus and, if fitted with an appropriate device, mark estrous females. A cow, sow or mare used for semen collection.

testis – primary male reproductive organ.

thermal (climatic) stress – changes in temperature or other weather related factors that produce a response.

thermoneutral zone – temperature range where animal does not have to use extra energy to conserve or dissipate heat.

thermoregulation – the regulation of body temperature.

tie stall – restraint facility by which animals are held by collars or chains around the neck.

tom – male turkey or cat.

total confinement – raising animals within enclosed buildings for their entire lives.

UHT – Ultra High Temperature heat processing results in a sterile product (140°C for 3-4 seconds).

upper critical temperature (UTC) – the environmental temperature above which an animal must begin to expend energy to prevent an increase in body temperature.

uterus – portion of the female reproductive tract where conceptuses develop prior to birth (womb).

vacuum packaging – the packaging of a product in the absence of oxygen.

virulence – the relative ability of a pathogenic microorganism to cause disease.

weaned – offspring removed from mother.

wether – a castrated ram.

white veal – the meat from a young calf fed primarily a milk based diet.

withdrawal period -the time when a drug must not be administered prior to marketing to insure that no residues remain in the meat or milk.

worms – Parasitic helminths

yearling – an animal between one and two years of age.

zconosis – diseases of animals that can be transmitted to humans.

zone of thermal neutrality – the thermoneutral zone or temperature range in which an animal does not have to use any extra energy to conserve or dissipate heat.

zygote – the product of fertilization, ie. a cell formed from the union of an oocyte and a spermatozoon.

 

• Abdominocentesis

The insertion of a needle into the abdominal cavity to remoe fluids.

• Abscess

A localized accumulation of pus; usually associated with infection.

• ACE inhibitor

Angiotensin-converting-enzyme (ACE) inhibitor: Drug which decreases he function of this particular enzyme. The angiotensin-converting-enzyme changes a compound called angiotensin I to angiotensin II. Angiotensin II is a potent blood vessel constrictor. ACE inhibitors, then, have the effect of dilating blood vessels, since less Angiotensin II is produced.

• Acid

A fluid containing a high proportion of hydrogen ions, giving the liquid a sour taste. Measured by pH units, with 1 the most acid, and 14 the least acid. Chemical reactions in the body have to take place at or near neutrality, pH 7.

• ACTH

Adrenocorticotropic hormone. A hormone, secreted by the pituitary gland, which stimulates the adrenal gland to work.

• Activated charcoal

Charcoal which has been treated to increase its adsorptive power (ability to have chemicals adhere to it); usd to treat various forms of poisoning.

• Active immunity

Immunity produced when an animal’s own immune system reacts to a stimulus e.g., a virus or bacteria, and produces antibodies and cells which will protectit from the disease caused by the bacteria or virus. Compare with ‘passive immunity.’

• Acute

Having a sudden and generally severe onset. See also Chronic.

• Addisons disease

Addison’s disease is also known as hypoadrenocorticism. I is a disease that results from a decrease in corticosteroid secretion from the adrenal gland. See article: Addison’s Disease (Hypoadrenocorticism) in Dogs.

• Adjuvant

A substance added to killed vaccines to stimulate a better immune response by the body. Common adjuvants contain aluminum compounds.

• Adrenal glands

Two small glands near the kidneys that produce many hormones required for life.

• Adrenaline

A hormone produced by the adrenal glands that elevates heart and respiration rates; also clled ‘epinephrine.’

• Adrenergic

Communication between the nerves and muscles that uses epinephrine as the ‘messenger.’ Adrenergic stimulation is whatis involved in the ‘flight or fight’ response, which means the body is alerted to a danger of some sort and prepares to basically run or fight. Adrenergic stimulation results in an increased heart rate, sweating, and increased blood pressure.

• Adsorbent

A solid substance which attracts other molecules to its surface.

• Adulticide

Medication formulated to kill adult forms of a parasite.

• Aerobic

Needing oxygen to live. See also Anaerobic bacteria.

• Aerobic bacteria

Bacteria that require oxygen to survive and grow.

• Agglutination

Clumping together.

• Albino

An animal that is completely whie because it lacks the ability to make pigment. Its eyes are pale blue or pink.

• Albumin

A protein in the blood responsible for the maintenance of osmotic (water) pressure in the blood; also binds (attaches)to large molecules in the blood and serves to transport them; produced by the liver; also called ‘serum albumin.’

• Aldosterone

A hormone secreted by the adrenal gland that stimulates sodium (and therefore water) retention and potassium excretion; important in blood pressure maintenance.

• Alimentary

Pertaining to food or the digestive tract.

• Alkaline

A substance with very few hydrogen ions, and a pH oer 7. Lye is strongly alkaline.

• Allergen

A substance that causes an allergic reaction, e.g., pollen.

• Alopecia

A loss of hair or baldness.

• Alveoli

The tiny microscopic areas of the lng where the actual exchange of oxygen and carbon dioxide into and out of the blood occurs. Also called alveolus and alveolar sacs.

• Aminoglycoside

A class of antibiotics which act by interfering with bacterial protein synthesis within the bacteria which results in the death of the bacteria. Antibiotics in this clss include gentamicin (Gentocin), kanamycin, neomycin, streptomycin, tobramycin, and amikacin. Many of these antibiotics are not well-absorbed from the animal’s digestive system, so are often administered as injections, or used topically.

• Amylase

Digestive enzyme, produced by the pancreas which breaks down carbohydrates and starches.

• Anabolic steroid

A type of steroid (not a corticosteroid like prednisone, cortisone, or dexamethasone) hich promotes the building of tissues, like muscle.

• Anaerobic bacteria

Bacteria which only live in an environment in which there is no or little oxygen, e.g., Clostridium tetani which causes tetanus.

• Analgesia

Pain relief.

• Anamnestic response

The faste and greater immune response produced by an animal who has previously encountered that specific antigen. Memory cells are responsible for this more efficient response. Also called ‘secondary response.’

• Anaphylaxis

Anaphylaxis is a rare, life-threatening, immediate allergic reaction to something ingested or injected. If untreated, it results in shock, respiratory and cardiac failure, and death. See article: Anaphylaxis in Dogs and Cats. ay also be referred to as anaphylactic shock or anaphylactoid reaction.

• Androgen

A hormone which produces male sexual characteristics, e.g., testosterone.

• Anemia

A condition in which the number of red blood cells present in the blood is lower tan normal.

• Anesthesia

Loss of sensation or feeling; induced artificially with drugs to permit painful procedures such s surgery.

• Angiography

The x-ray of vessels after injecting a contrasting fluid.

• Angiotensin-converting-enzyme inhibitor

(ACE inhibitor) Drug which decreasesthe function of this particular enzyme. The angiotensin-converting-enzyme changes a compound called angiotensin I to angiotensin II. Angiotensin II is a potent blood vessel constrictor. ACE inhibitors, then, have the effect of dilating blood vessels, since less Angiotensin II is produced.

• Anisocoria

A condition in which the pupils of the eyes are not of equal size.

• Anorexia

Loss of appetite.

• Anterior

Positioned in front of aother body part, or towards the head of the animal. Opposite of posterior.

• Anthelmintic

Medication which kills certain types of intestinal worms; dewormer.

• Antibiotics

Usually refers to drugs administered to kill or inhibit the growth of bacteia; not effective against viral infections.

• Antibody

Small disease-fighting proteins produced by certain types of cells called ‘B cells.’ The proteins are made in response to ‘foreig’ particles such as bacteria or viruses. These antibodies bind with certain proteins (antigens) on foreign particles like bacteria, to help inactivate them. See also Antigen.

• Antibody titer

A measurement of the amount of antibodies in the blood. The test to measure antibodies is usually performed by making a number of dilutions of the blood and then measuring at what dilution there is sufficient antibody to react in the test. For example, a titer of 1:8 (one to eight) means the blood can bediluted to one part blood and seven parts saline and still produce a positive reaction in the test. The higher the titer (1:16 is higher than 1:8), the more antibody is present.

• Anticholinergic

Stopping the communications between certain nerves and muscles of the body including those of the gastrointestinal tract and heart. These nerves are called ‘parasympathetic’ nerves and do such things as constrict the pupils of the eye, stimulate contractions of the muscles in the intestine, and slow the heart rate. Anticholinergic drugs would have the effect, then, of dilating the pupil, slowing contractions of the intestines, and increasing the heart rate.

• Anticholinesterase

A drug that blocks the enzyme acetylcholinesterase; this results in stimulation of the parasympathetic nervous system.

• Anticoagulation

Stopping the blood clotting process.

• Anticonvulsant

A drug used to prevent or decrease the severty of convulsions.

• Antidiuretic hormone

A hormone produced by the pituitary gland that reduces the prodution of urine in the kidneys and therefore prevents water loss; also called ‘vasopressin.’

• Antiemetic

An agent that decreases or stops vomiting.

• Antifungal

Drugs administered to kill or inhibit the growth f fungi (plural of fungus).

• Antigen

A molecular structure on surfaces of such particles as bacteria and viruses. This strucure is recognized by the body as ‘foreign’ and stimulates the body to produce special proteins called antibodies to inactivate this foreign invader. See also Antibody.

• Antiprotozoal

An agent that kills protozoa, which are one-celled organisms such as Giardia.

• Antipruritic

Relieves itching.

• Antipyretic

A substance used to reliee fever.

• Antiseptic

A substance which inhibits the growth of bcteria, but does not kill them.

• Antispasmodic

An agent that relieves or decreases spasms in muscle. The muscle could include’smooth muscle’ which is the type of muscle in intestines that causes them to contract and move food through the digestive system.

• Antitussive

Cough suppressant.

• Anuria

The condition of complete failre in the function of the kidneys such that no urine is produced.

• Anus

A muscular opening at the end of the digestive tract where fecal waste is expelled.

• Aplastic anemia

A serious condition in which red blood cells, white blood cells, and platelets re not produced in sufficient quantity.

• Aquaculture

The (usually commercial) captive raising of fish, corals, and other aquatic life for aquariums, food, and scientific purposes.

• Aqueous humor

The fluid found within the eyeball which provides nourishment to the interior eye structures and keeps the eyeball inflated.

• Arrhythmia

A variation from normal heart rhythm.

• Arteries

Thick walled vessels that carry blood away fro the heart to the lungs and body tissues; the pulmonary arteries carry deoxygenated blood to the lungs, but all other arteries carry oxygenated blood.

• Arthritis

Inflammation and swelling in the joints; has multiple causes including lameness.

• Articular

Pertaining to a joint.

• Ascarid

Roundworm. See article: Roundwoms in Dogs and Cats.

• Ascites

Fluid accumulation in the abdomen.

• Aspirate

Withdraw fluid or cells through the use f suction – usually the suction produced by pulling back on the plunger of a syringe attached to a needle which is inserted into the area to be sampled. Also the breathing in of a fluid or foreign substances.

• Asymptomatic

A term used to decide a condition in which no symptoms are present.

• Ataxia

A lack of muscle coordination, usually causing an abnormal or staggered gait.

• Atoll

A coral island consisting of a reef surrounding a lagoon.

• Atopy

An allergy to something that is inhaled such as pollen or house ust. Also called ‘inhalant allergy.’ See articles in the Allergies section.

• ATP

Adenosine triphosphate; a compound used for energy by cells.

• Atrial fibrillation

A heart condition in which the atria (chambers of te heart that receive the blood) contract rapidly, irregularly, and independently of the ventricles (the chambers of the heart that pump the blood). This greatly decreases the efficiency of the heart and its ability to move blood.

• Atrial flutter

A heart condition in which the atria (chambers of the heart that receive the blood) contract rapidly, irregularly, and independently of the ventricles (the chambers of the heart that pump the blood). This greatly decreases the efficiency of the heart and its ability to move blood.

• Atrium

(Plural atria) The two chambers of the heart that receive blood. The right atrium receives blood from the body. The left atrium receives oxygenated blood from the lungs.

• Atrophy

An abnormal decrease in size of an organ or tissue.

• Attenuated

Weakened. An attenuated virus is one which has been chaged such that it will no longer cause disease. An attenuated virus would be used in a modified live vaccine.

• Auscultate

To listen for sounds produced within the body, usually with the aid of a stethoscope.

• Autoimmune

A condition in which the immune system attacks the body’s own tissues. To properly function,the immune system must identify foreign substances such as bacteria, viruses, parasites, slivers, etc., and it must be able to distinguish normal body tissue from these foreign substances. If it fails to distinguish the difference, it attempts to destroy the tissue it wrongly identifies as foreign. For example, in autoimmune hemolytic anemia, the body destroys its own red blood cells. In rheumatoid arthritis it attacks the cells in the joints.

• Axilla

Armpit.

• Azotemia

The presenceof increased nitrogenous (containing nitrogen) waste products in the blood as a result of kidney malfunction.

B

• B cell

Also called ‘B lymphocyte.’ The type of lymphocyte which produces antibody. Compare with ‘T cells.’

• Bacteriocidal

A description of an agent that kills bacteria.

• Bacteriostatic

A description of an agent that stops the growth (repoduction) of bacteria, but does NOT kill them.

• Bacterium

Microscopic organisms that lack nuclei and other organelles; pathogenic species cause disease, while nonpathogeic species are harmless.

• Barium Study

A procedure in which a pet is given barium to swallow or as an enema, followed by x-ray exams to locate disorders of the esophagus, stomach r intestine.

• Benign

A mild illness or non-malignant form of a tumor. Benign tumors usually have well defined edges and tend to grow slowly.

• Beta blockers

Heart medications which block certain receptors in the heart called beta receptors. The beta receptors receive signals hich generally increase the heart rate. If the heart rate is abnormally fast and uneven, beta blockers will help stabilize the rate and rhythm of contractions.

• Beta-carotene

A plant pigment which can be converted to Vitamin A by many animals, but not by cats.

• Beta-lactamases

Enzymes produced by some bacteria which inactivate certain types of penicillin, thus makin the bacteria resistant to them.

• Bilateral

On both sides.

• Bile

A liquid produced by the lver, stored in the gall bladder, and dispensed into the small intestine as needed; aids in the digestion and absorption of fats.

• Bile acids

Certain compounds produced by the liver, bound to amino acids, and excreted in the bile to aid in the digestion of fats.

• Bilirubin

An orange-yellow pigment in bile that is a product of red blood cell breakdown; it is normally excreted with the urine or feces,and a buildup in the body can cause jaundice.

• Biopsy

The surgical removal of a small amount of abnormal tissue, usually of tumors, for diagnosis.

• Bitch

A female dog.

• Bladder

A sac that receive and holds a liquid until it is excreted, e.g., urinary bladder, gall bladder; in fish, the swim bladder holds air.

• Blepharospasm

Spasm of the eyelids often resulting in complete closure of the lids due to eye pain, such as seen with a scratch on the cornea.

• Bloat

Filling of the stomach with air.

• Blood gases

Gases, such as oxygen or carbon doxide, that are in the blood.

• Blood glucose

A graph of blood glucose levels over time. At the time of insulin injction, and at regular intervals throughout the day, the level of glucose in the blood is determined through laboratory testing.

• Bone marrow

A soft tissue composed of blood vessels and connective tissues found at the center of bones; the primary function is blood cell production.

• Bone marrow suppression

A condition in which the cells of the bone marrow which produce red blood cells, white blood cells, and platelets are inhibited. This ay result from the use of certain drugs, such as anti-cancer agents.

• Borborygmus

The sound of gas moving through the intestine; bowel sounds.

• Bradycardia

An abnormal slowing of the heart rate.

• Bronchi

The plural of bronchus, the large air passages ofthe lungs.

• Bronchiole

The small airways in the lung that come off of the larger bronchs; bronchioles are 1 mm or less in diameter.

• Bronchodilator

Medication which opens up the main air passages to the lungs.

• Bronchoscope

A tool designed to facilitate inspection of the trachea and bronchi; used in both diagnostic and therapeutic procedures.

• Bronchoscopy

The internal inspection of the trachea and bronchi using a bronchoscope.

• Bronchospasm

A condition in which the muscles surrounding the air passages to the lungs contract, narrowing the passages.

• BUN

Short for ‘blood urea nitrogen,’ a blood test that estimates kidney function.

 

C

• Cachexia

Extreme weight loss.

• Calcified

The hardening of tissue through the influx of calcium, usually as a result of chronic inflammation.

• Calculus

(Plural calculi) Abnormal stone-like structure(s) usually composed of mineral salts, e.g., a bladder calculus is the same thing as a bladder stone.

• Calorie

The unit of measurement of energy derived from digested food. Fat contains about twice as many calories per gram as protein or carbohydrate.

• Cancer

A malignant tumor.

• Candida

A certain genus of yeast which can cause disease in humans and animals; an infection with Candida is called candidiasis.

• Canine

Pertaining to dogs.

• Carapace

The upper shell of a turtle or tortoise.

• Carbohydrate

Compounds made up of chains of sugar units. Simple carbohydrates include table sugar (sucrose), milk sugar (lactose), and fruit sugar (fructose). Complex carbohydrates are very long chains held together by bonds that may not be digestible in the stomach and intestine of a carnivore. Starch is a digestible complex carbohydrate. Seed hulls such as oat bran are digestible by ruminants and horses, but not carnivores.

• Carcinogen

A substance which causes cancer.

• Carcinoma

A malignant cancer that arises from the epithelial tissues of the body such as the skin, intestinal tract, and bladder.

• Cardiac

Related to the heart.

• Cardiomyopathy

Diseases of the heart muscle; does not include diseases of the valves of the heart or congenital defects.

• Cardiopulmonary

Relating to the heart and lungs.

• Cardiovascular

Related to the heart and blood vessels.

• Carnivore

An animal whose natural diet includes meat.

• Carpus

The wrist (front leg) of dogs and cats.

• Carrier

An animal which harbors an infectious organism, such as a virus, bacteria, or parasite. The animal does not appear ill, but can still transmit the organism to other animals by direct contact or releasing the organisms (bacteria, protozoa, viruses) into the environment in the stool, urine, respiratory secretions, or vaginal discharges.

• Castration

The removal of the sex organs making the animal incapable of reproduction; the correct use of the word can be used to describe both male and female animals, but it is commonly used to describe only males.

• Cataract

A cloudiness of the lens of the eye, reducing vision and giving the eye a pearly appearance.

• Caudal

A directional term used to refer to an area more toward the cauda, or tail region; opposite of cranial.

• Caval syndrome

Disease caused by large numbers of worms in the right side of the heart and vena cava, which results in blood circulation problems in the liver leading to the breakdown of red blood cells, anemia, weakness, and collapse.

• Cecum

A blind sac that opens into the colon; found in many animals.

• Cell-mediated immunity

A machine that rapidly spins liquid samples and separates out the particles by their density.

• Centrifuge

The immunity that is the result of either special lymphocytes directly killing the foreign invader, or lymphocytes (T cells) releasing special chemicals which activate macrophages to kill the invader. Compare with ‘humoral immunity.’

• Cerebellum

A portion of the brain, located on the brainstem, that controls coordination.

• Cerebral

Relating to the part of the brain known as the cerebrum.

• Cerebrum

The largest portion of the brain that performs all higher cognitive functions and is situated in the front part of the cranial cavity.

• Chelation

Binding of a substance to a metal, thus helping the body to remove it.

• Chemotherapy

Treatment of a disease with chemical agents (drugs); the term is most commonly used to describe the treatment of cancer with medication.

• Choana

(Plural choanae) An opening between the nasal cavity and oropharynx (mouth) in birds and reptiles.

• Cholangiohepatitis

Inflammation of the gall bladder, bile ducts, and liver

• Cholangitis

Inflammation of a bile duct; see cholecystitis.

• Cholecystitis

Inflammation of the gallbladder; see cholangitis.

• Chondroitin

Decreases the activity of enzymes which break down cartilage in a joint.

• Chondroprotective agent

A nutritional supplement that protects cartilage.

• Chronic

Of a long duration: a chronic illness persists for weeks, months, or even for the life of animal. See also acute.

• Chronic superficial keratitis

A chronic condition of the eye in which blood vessels grow across the cornea (the clear surface of the eye). The cornea looks hazy and sometimes reddened; it may eventually take on a dark pigment. This condition is also called pannus.

• Cirrhosis

A liver disease caused by the replacement of damaged cells with connective tissue; severe scarring can eventually cause liver failure.

• Class I, II, III, IV medications

Drugs are classified by the Drug Enforcement Administration of the Department of Justice depending upon such criteria as the potential for human abuse.

• Clinical study

A planned examination of the effectiveness of a new drug or treatment for a disease as compared to a control group not receiving the treatment; also called a clinical trial.

• Cloaca

A common tube-like structure through which feces, urine, and reproductive fluids/eggs pass in birds, turtles, and other lower vertebrates.

• Clotting factors

Protein components in the blood which help it to clot. Clotting is a complex mechanism. In addition to platelets, clot formation is the result of a long chain of chemical reactions carried out by individual molecules called ‘clotting factors.’ Each factor is numbered such that factor I leads to a reaction with factor II forming a new substance. This then reacts with factor III and so on to factor XII.

• Clutch

The uninterrupted series of eggs laid by a hen, usually 2-6 depending on the bird species.

• CNS

Central nervous system. Includes the brain, spinal cord, and the nerves leading from them.

• Coagulation

The process of clotting.

• Coagulopathy

A condition affecting the blood’s ability to form a clot.

• Coccidia

A one-celled parasite in the category of protozoa. In dogs and cats, coccidia are generally parasites of the intestinal tract. See article: Coccidia in Dogs and Cats.

• Cognitive dysfunction

A common medical condition in older dogs that results from abnormal brain function, causing certain behavior changes such as disorientation, housebreaking problems, and changes in sleeping patterns and interactions with others.

• Cold-blooded

Having a body temperature that is not regulated internally, but varies with the environmental temperature. Turtles, lizards, and snakes are cold-blooded.

• Colitis

An infection or inflammation of the colon.

• Colon

A part of the digestive tract, specifically the part of large intestine that extends from the cecum to the rectum.

• Colostrum

The antibody-rich first milk produced immediately before and after giving birth.

• Coma

Being in a state of unconsciousness.

• Comedo

A blackhead, usually the result of a plugged gland within the skin.

• Complete blood count

A count of the total number of cells in a given amount of blood, including the red and white blood cells; often referred to as a ‘CBC,’ it is one of the most common tests done to check for abnormalities of the blood.

• Computerized tomography scan (CT scan)

A radiological imaging procedure that uses x-ray pictures to produce “slices” through a patient’s body; also called a computerized axial tomography (CAT).

• Conception

The onset of pregnancy, when the fertilized egg attaches to the uterus.

• Congenital

A characteristic of an animal that is present at birth. It may be inherited or induced by events that occur during pregnancy.

• Conjunctiva

A thin membrane which lines the inside of the eyelids and covers part of the eyeball.

• Conjunctivitis

An inflammation of the lining of the eyelids; may cause pain, redness, itching, and a discharge.

• Constipation

A condition in which the movement of food through the digestive system is longer than normal; often results in hard, dry stool.

• Contrast agents

A substance given orally or injected into a patient that makes the affected tissue easier to identify on an x-ray.

• Contusion

An injury to underlying tissues without breaking the skin; a bruise.

• Coprophagia

Eating dung or fecal matter; normal behavior in some animals, such as rabbits.

• Core vaccine

Vaccine which should be given to all animals of certain species, example, parvovirus vaccine in dogs or panleukopenia in cats (see noncore vaccine).

• Cornea

The clear part of the front of the eye which allows light in.

• Corticosteroid

Hormones produced by the adrenal gland which are important to almost every function of cells and organs. They are divided into two groups: glucocorticoids and mineralocorticoids. Glucocorticoids regulate protein, carbohydrate, and fat metabolism. Mineralocorticoids regulate electrolyte balances.

• Cortisol

The main glucocorticoid; a hormone naturally produced by the adrenal gland; it is synthesized commercially as hydrocortisone and is used to reduce inflammation.

• Coumestan

Estrogen-like substance produced by certain plants such as alfalfa; types of phytoestrogen.

• Coumestral

Estrogen-like substances produced by certain plants such as alfalfa; types of phytoestrogen.

• Cranial

A directional term used to refer to the area near the cranium, or head region; opposite of caudal.

• Crop

An organ between the esophagus and stomach of many domestic birds, which serves as a temporary food storage organ.

• Crust

Area of dried fluid or cells on the skin. The fluid may have been blood, serum, pus, or medication.

• Culture

The process in which a sample of fluid or tissue is taken from an animal and placed in special media which allows the bacteria, virus, etc., to grow (reproduce) in the laboratory.

• Cushings disease

Cushing’s disease is also known as hyperadrenocorticism. It is a disease that results from an increase in corticosteroid secretion from the adrenal gland. See article: Cushing’s Disease (Hyperadrenocorticism) in Dogs.

• Cutaneous

Relating to the skin.

• Cyanosis

Bluish or grayish color to the skin and gums which occurs when the animal has insufficient oxygen.

• Cyst

An abnormal sac-like structure that is lined with cells which produce a liquid or thick material.

• Cystitis

Inflammation of the urinary bladder.

• Cystocentesis

A method to obtain an uncontaminated urine sample in which a needle is passed through the abdomen into the urinary bladder, and the urine is collected in a syringe attached to the needle.

• Cytokines

Compounds produced by certain cells, which act as messengers to control the action of lymphocytes and other cells in an immune response.

• Cytology

The study of cells; often refers to the microscopic examination of a sample taken from the skin or lesion to look for the cause of a condition.

• Cytoplasm

Substances which make up the inside of a cell and surround the nucleus of the cell which contains the genetic material.

D

• DEA

Drug Enforcement Administration. The federal agency which regulates the manufacture, dispensing, storage, and shipment of controlled substances including medications with human abuse potential.

• Decontaminate

Remove injurious material.

• Defecation

The elimination of feces from the rectum.

• Dehydration

A condition in which the body loses more water than it takes in.

• Dermal

Relating to the skin.

• Dermatitis

An inflammation of the skin.

• Dermatophyte

Fungus that causes ringworm; include Trichophyton, Microsporum, and Epidermophyton.

• Descenting

The removal of the anal sacs of a carnivore to prevent the animal from releasing the very strong-smelling secretion.

• Dextrose

A commonly used name for glucose (sugar) solutions given intravenously to treat fluid or nutrient loss.

• Diabetes mellitus

A metabolic disease caused by failure of the pancreas to produce insulin, a hormone that allows blood sugar (glucose) to be taken up by cells that require it for function.

• Diagnostic tests

Procedures run to find the cause of disease or discomfort; tests used to make a diagnosis.

• Dialysis

A process which involves removing waste products from the body.

• Diarrhea

A condition in which the movement of food through the digestive system is faster than normal; often results in the frequent passing of abnormally loose or watery stool.

• Diestrus

The stage of the estrus cycle which occurs after the animal goes out of heat (also called Diestrous).

• Dietary indiscretion

Eating what one should not. Dogs with dietary indiscretion eat garbage, dead fish on shore, etc.

• Digestibility

Expressed as a percent, is a measure of the content of food that is retained in the body after food is eaten. The difference between the weight of food eaten and the weight of stool produced, divided by the weight of the food.

• Digestive system

The organ system including the mouth, teeth, tongue, esophagus, stomach, intestines, and various glands that functions to ingest, digest, and absorb nutrients.

• Digitalis glycosides

Class of drugs including digitoxin and digoxin, which are drugs derived from the Digitalis purpurea plant, and used in the treatment of congestive heart failure.

• Dilated cardiomyopathy

A heart condition in which the heart enlarges, but the heart muscle becomes thinner.

• Dinoflagellate

Single-celled algae, mainly marine and often with a cellulose shell; some species may be luminescent, and some cause the red tides that are extremely toxic to marine life.

• Disinfection

The act of using chemicals or heat to kill germs.

• Distemper

Canine distemper is a viral disease that causes a severe and often fatal systemic illness in dogs and their close relatives. Distemper is also fatal in animals such as raccoons, and mustelids including skunks, mink, and ferrets.

• Diuresis

Increase in urine production.

• Diuretic

Agent which increases the secretion of urine, ridding the body of excess fluid.

• Diurnal

Active during the day, opposite of nocturnal, which means active during the night.

• DNA

Deoxyribonucleic acid, the chemical compound that occurs in cells and is the basic structure for genes.

• Domestic animal

An animal that has been housed and fed by man for generations and has little fear of man as a result. Some domestic animals learn to depend on human provision so completely that they have little ability to survive if returned to a natural habitat.

• Dry Eye

Keratoconjunctivitis sicca (KCS) is the technical term for a condition also known as ‘dry eye.’ It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.

• Duodenum

The first portion of the small intestine extending from the stomach to the jejunum; most chemical digestion and absorption of nutrients occurs here.

• Duration of immunity

Length of time an animal is protected from a disease. Vaccines for some diseases provide long durations of immunity (years), while vaccines for some other diseases only provide immunity that lasts for 6 months.

• Dysecdysis

Abnormal shedding of the skin in reptiles.

• Dysphagia

Difficulty swallowing.

• Dysplasia

An abnormal tissue development, common in the bones of the canine.

• Dyspnea

Shortness of breath.

• Dystocia

Difficult birth.

• Dystrophic

Disorder caused by incorrect nutrition.

• Dysuria

Difficult or painful urination.

E

• Ear canal

The tube that connects the external ear with the ear drum.

• Ear drum

The membrane that divides the outer ear from the inner ear, where the mechanism of hearing takes place. The membrane prevents infection from reaching the inner ear, as well as vibrating to amplify sounds.

• Ear mites

Small parasitic insects that live in the ear canal of an animal, and that are able to survive outside the ear for only very short periods of time.

• Ecdysis

Shedding of the external layers of the skin in reptiles.

• ECG

A printout of an analysis of the electrical activity in the heart.

• Echocardiogram

The image produced by performing an ultrasound examination of the heart.

• Ectoparasite

A parasite that lives on the outside surface or skin of another animal. Ectoparasites include fleas, ticks, lice, and mange mites.

• Ectopic

Non-malignant tissue growing in an unusual location (e.g., an ectopic pregnancy is conception of a normal embryo outside the normal location, which is the uterus).

• Edema

A condition in which the tissues of the body contain too much body fluid. The fluid accumulation may cause swelling in the affected area.

• EKG

A printout of an analysis of the electrical activity in the heart.

• Electrocardiogram

A printout of an analysis of the electrical activity in the heart.

• Electrocautery

An instrument with a very hot tip, heated by electricity, is applied to a tissue. Electrocautery may be used to make an incision, remove a mass, or to stop bleeding.

• Electrolyte

Chemically, an element when dissolved in water, will cause the solution to transmit electricity. In medicine, certain elements in the blood which are critically important to life, including sodium, potassium, chloride, calcium, and phosphorous.

• Electroretinography

The recording of electrical changes in the retina of the eye in response to stimulation by light.

• Elizabethan collar

A large, plastic, cone-shaped collar used on cats, dogs, and birds to prevent them from licking or biting at skin, wound dressings, or casts.

• Emaciation

The severe loss of body weight; body weight is generally less than 50% of that in a normal animal.

• Emesis

Vomiting.

• Encephalitis

Inflammation of the brain; often caused by a virus.

• Encephalopathy

Any degenerative disease of the brain. Causes include liver disease resulting in the buildup of toxic by-products of metabolism, heavy metal (e.g., lead) poisoning, and loss of blood supply.

• Endocrine

Pertaining to the secretion of hormones. The endocrine system consists of various glands which produce hormones.

• Endoscope

A long flexible instrument which can be passed into the body to view various structures through the use of fiber optics.

• Endotracheal tube

This tube is placed into the animal’s trachea (windpipe) to allow the oxygen and gases to be breathed into the lungs.

• Enteral feeding

A method to feed an animal in which a tube is placed through the body wall into the intestine, and a nutritious liquid is forced through the tube into the intestine.

• Enteritis

An inflammation of the intestines.

• Envenomation

The act of injecting a poisonous material (venom).

• Enzyme

Enzymes are special proteins produced by cells which cause chemical changes in other substances, but which are not themselves changed in the process.

• Eosinophil

A type of white blood cell that commonly increases in numbers as a response to parasites and allergies.

• Eosinophilia

A condition in which there are more than the usual number of eosinophils in the circulating blood.

• EPA

Environmental Protection Agency. The agency of the federal government which licenses pesticides and herbicides.

• Epidermis

The top layer of the skin.

• Epiphora

An overflow of tears upon the cheeks due to a blockage or narrowing of the tear ducts.

• Epistaxis

Bleeding from the nose.

• Erosion

A shallow defect in the skin. When healed, it will not cause a scar.

• Erythema

Redness of the skin caused by blood clogging in small blood vessels.

• Erythrocyte

Red blood cell; contains hemoglobin, which carries oxygen to the tissues.

• Esophageal reflux

A condition in which stomach contents move backward into the esophagus, i.e., heartburn.

• Esophagus

The muscular tube for the passage of food from the mouth to the stomach.

• Estrogen

A female hormone produced by the ovaries, which results in the onset of estrus.

• Estrus

The time when a female animal is fertile and receptive to the male. Also known as a heat period.

• Exophthalmos

The abnormal outward protrusion (bulging) of the eye.

• Exotic

An animal not native to the geographical area where it is living.

• Extensor rigidity

A condition in which muscles contract and tend to straighten the limb, prevent it from relaxing.

• Extracranial

Originating external to the cranial (brain) cavity.

• Extrahepatic

Outside of the liver.

F

• False negative test result

The result of a diagnostic test is negative; but the animal actually does have the condition tested for.

• False positive test result

The result of a diagnostic test is positive; but the animal actually does not have the condition tested for.

• FDA

Food and Drug Administration. The federal agency which approves drugs and medications for use in animals and people.

• Feces

Body wastes excreted through the anus from the large intestine; also called stool.

• Feline

Pertaining to cats.

• Fetal

Pertaining to an unborn animal, or fetus.

• Fetus

The developing young in the uterus before birth.

• Fine needle aspirate

Suction is applied to a hollow needle which has been inserted into tissue and a core of the tissue is withdrawn to culture and/or examine microscopically.

• First generation

First generation: A description of medications developed from an earlier form of the medication. First generation medications were developed from the original form of the drug; second generation medications are adaptations of first generation drugs; third generation drugs are adaptations of second generation, etc.

• Flatulence

Increased stomach or intestinal gas.

• Flea dip

A solution made to kill fleas, applied to an animal and not rinsed off, to allow it to have residual action.

• Fluoroscopy

An x-ray procedure in which x-rays are transmitted through the body onto a fluorescent screen; beneficial in that movement of joints or organ systems can be observed (e.g., the movement of material through the esophagus, stomach, and intestines).

• FLUTD

Feline lower urinary tract disease; a condition in cats characterized by blood in the urine, urination outside of the litter box, and straining to urinate. The name for this condition was previously called feline urological syndrome (FUS).

• Follicle

The group of cells in the skin in which a hair or feather develops.

• Foreign body

Any abnormal substance within the body. Examples include wood slivers, ingested cloth or balls, glass in the feet, etc.

• Fracture

A break in the bone; generally caused by trauma, twisting, or weakened bone structure due to disease.

• Free radical

Atom which carries an unpaired electron; free radicals can potentially injure cells and may be responsible for numerous age-related diseases.

• Fungicide

A drug that kills fungi.

• FUS

Feline urological syndrome; a condition in cats characterized by blood in the urine, urination outside of the litter box, and straining to urinate. The name for this condition is now called feline lower urinary tract disease (FLUTD).

G

• Gait

The manner or style of movement; often used to assess horses or dogs for lameness.

• Gastric

Relating to the stomach.

• Gastric lavage

To flush out the stomach.

• Gastritis

Inflammation of the stomach.

• Gastrointestinal

Also known as GI. Pertaining to the stomach and intestines. The term ‘digestive system’ includes the mouth, gastrointestinal tract, anus, pancreas, and liver.

• Germs

Any microscopic organism that can potentially cause disease; includes viruses, bacteria, and fungi.

• Gestation

Pregnancy.

• Gingival

Relating to the gums.

• Gingivitis

Inflammation of the gums.

• Glaucoma

Increased pressure within the eye caused by an accumulation of fluids; can lead to blindness if left untreated.

• Glipizide

An oral medication that can be used to control blood glucose levels in some diabetic cats who still have some insulin production.

• Glomerulus

This literally means a small cluster; commonly used to refer to the renal glomerulus, the area of blood filtering in the kidney.

• Glucocorticoid

Hormones produced by the adrenal gland which regulate protein, carbohydrate and fat metabolism, and are important to almost every function of cells and organs. They also stabilize cell membranes which is an important part of their function in treating allergic reactions. Also called glucocorticosteroids.

• Glucocorticosteroid

Hormones produced by the adrenal gland which regulate protein, carbohydrate and fat metabolism, and are important to almost every function of cells and organs. They also stabilize cell membranes which is an important part of their function in treating allergic reactions. Also called glucocorticoids.

• Glucosamine

One of the building blocks the body uses to make new cartilage.

• Glucosuria

Glucose in the urine. (Also called glycosuria.)

• Glycogen

A storage form of glucose in the body.

• Glycosaminoglycans

Compounds which serve as the building blocks of cartilage, which covers the ends of bones within a joint. Glucosamine and chondroitin are necessary for the body to make glycosaminoglycans.

• Gram

A measure of weight. 28 grams = 1 oz.; 454 grams = 1 lb.

• Gram negative

A classification of bacteria based upon their lack of retention of a certain stain in the laboratory. The staining quality is based on the structure of the cell wall surrounding the bacteria. This structure of the cell wall influences which antibiotics will kill the bacteria. This laboratory staining method was developed by Hans Gram in 1884.

• Gram positive

A classification of bacteria based upon their uptake of a certain stain in the laboratory. The staining quality is based on the structure of the cell wall surrounding the bacteria. This structure of the cell wall influences which antibiotics will kill the bacteria. This laboratory staining method was developed by Hans Gram in 1884.

• Granuloma

The formation of a nodule as a result of inflammation.

 

H

• H2 antagonist

A compound which binds (attaches) to the area on a cell at which histamine also binds. By binding at the same site, the antagonist blocks histamine from binding and prevents histamine from producing its effects, which include the production of stomach acid.

• Half-life

The time required for the level of a substance in the body (e.g., a drug or toxin) to be reduced by half.

• Head pressing

Pressing the head against a wall or other hard object.

• Heart block

A condition in which the electrical impulses of the heart are not properly conducted from the atria (chambers which receive the blood) to the ventricles (chambers which pump the blood).

• Heartworm

A species of parasitic worm (Dirofilaria immitis) that lives and reproduces in the chambers of the heart of an animal. Microscopic, immature worms (microfilariae) circulate in the blood and are taken in by mosquitoes that bite the animal. Microfilariae mature in the mouthparts of the mosquito and infect another susceptible animal bitten by the same mosquito.

• Heinz body

A condition in which the red blood cells are destroyed and this results in anemia. The specific type of anemia is called ‘Heinz body anemia’ because the red cells develop an abnormality called a ‘Heinz body’ which can be seen under the microscope. This anemia can occur as a reaction to certain medications and also in cats who eat onions.

• Hemangiosarcoma

A malignant tumor of the blood vessels, usually occurring in the skin, liver, spleen, right atrium of the heart, and muscle; also called angiosarcoma.

• Hematocrit

PCV (Packed Cell Volume), hematocrit: A laboratory test to monitor relative number of red blood cells present in the blood. A blood sample is placed in a tiny glass tube and spun in a centrifuge. The cells are heavier than the plasma and are compacted at one end of the tube. After the tube is spun, it is examined and the packed cell volume is determined as the percentage of the red cellular portion relative to the total amount of blood in the tube (i.e. remainder being the plasma). The normal for dogs is 40-59 and cats is 29-50.

• Hematology

The study of blood, its physiology and pathology.

• Hematoma

A mass of blood within the tissues. Generally, the result of trauma to the blood vessels or abnormal blood clotting.

• Hematuria

A condition of blood in the urine.

• Hemodialysis

A process used to remove waste products from the blood.

• Hemoglobin

A protein inside of red blood cells, responsible for the binding and transport of oxygen to the body tissues (Hb).

• Hemolytic

Causing the red blood cells to break open.

• Hemoptysis

Blood in the sputum.

• Hemorrhage

To bleed excessively; may be the result of injury or blood clotting abnormalities.

• Hemostat

A small surgical instrument used to clamp blood vessels to prevent bleeding.

• Hepatic

Pertaining to the liver.

• Hepatic fibrosis

Scarring of the liver

• Hepatitis

An inflammation or infection of the liver.

• Hepatomegaly

Enlargement of the liver.

• Herbivore

Animal that eats primarily plants and vegetation.

• Hernia

The protrusion of an organ through an abnormal opening.

• High titer vaccine

A modified live vaccine that contains a higher number of virus particles than the ‘average’ vaccine. High titer vaccines can generally elicit an immune system response in young animals who have a maternal antibody level that would prevent them from responding to an ‘average’ vaccine.

• Histamine H2 receptor antagonist

A compound which binds (attaches) to the area on a cell at which histamine also binds. By binding at the same site, the antagonist blocks histamine from binding and prevents histamine from producing its effects, which include the production of stomach acid.

• Hob

A male ferret.

• Hormone

Chemical substance produced by one part of the body which serves as a messenger to or regulator of the processes of another part of the body.

• Host

The organism in or on which a parasite lives. For example, dogs and cats are hosts for fleas and roundworms.

• Humoral immunity

The immunity that is the result of antibody production by B cells. Compare with ‘cell-mediated immunity.’

• Hybrid

An animal that has parents of two different species, for instance, a mule’s mother is a horse and its father is a donkey.

• Hydrocephalus

A condition of fluid accumulation in the ventricles (spaces) of the brain; the swelling generally creates pressure on the brain tissues and can cause severe damage if not treated properly.

• Hyper

A prefix meaning abnormally high or excessive.

• Hypercalcemia

An increased level of calcium in the blood.

• Hyperesthesia

Abnormal sensitivity to touch, pain, or other sensory stimuli.

• Hyperglycemia

Higher than normal blood glucose level.

• Hyperkalemia

Increased level of potassium in the blood.

• Hyperphosphatemia

Elevated blood phosphate levels.

• Hyperpigmentation

An increased dark color in the skin caused by the pigment ‘melanin.’

• Hyperplasia

An increase of the number of cells within an organ.

• Hyperplastic

Abnormal increase in the amount of tissue, e.g., a hyperplastic ear would have increased numbers of cells in the ear canal, sometimes to the point of closing off the ear canal. In prostatic hyperplasia, the prostate enlarges due to an increased number of normal, not cancerous, cells.

• Hyperreactive

Producing an exaggerated, or greater than normal response to a stimulus.

• Hypersensitive

A type of allergic condition in which the body overreacts to a certain agent such as a bee sting or medication.

• Hypertension

Blood pressure above normal.

• Hyperthermia

An increase in body temperature above normal.

• Hyperthyroidism

A condition, more commonly seen in cats, in which the thyroid gland produces too much thyroid hormone. See article: Hyperthyroidism in Cats.

• Hypertrophy

An increase in the size of a tissue or organ due to the enlargement of existing cells.

• Hyperventilate

An increase in the rate and/or depth of respiration such that the body loses too much carbon dioxide.

• Hypo

A prefix meaning abnormally low or deficient.

• Hypoglycemia

Lower than normal blood glucose level.

• Hypokalemia

Lower than normal level of potassium in the blood.

• Hypoplasia

Inadequate or defective development of tissue.

• Hypotension

Blood pressure below normal.

• Hypothermia

A decrease in body temperature below normal.

• Hypothyroidism

A condition, more common in dogs, in which the thyroid gland does not produce enough thyroid hormone. See article: Hypothyroidism in Dogs.

• Hypovitaminosis A

A condition in which the body suffers from a deficiency in Vitamin A.

• Hypoxia

Low oxygen level in blood and tissues.

I

• Iatrogenic

A condition resulting from the action of the doctor; e.g., an allergic reaction resulting from administration of an injection by a veterinarian.

• Icterus

Commonly referred to as jaundice. A yellowing of the tissues, usually as a result of abnormal liver function.

• IDDM

Insulin dependent diabetes mellitus (IDDM): A form of diabetes in which so little insulin is produced that supplemental insulin must be given for the animal to live. Also called Type I diabetes mellitus.

• Idiopathic

Of unknown cause.

• Ileus

A condition in which there is an absence of muscular contractions of the intestine which normally move the food through the system; can result in an intestinal obstruction.

• Immune system

The body’s defense system which recognizes infectious agents and other ‘foreign’ compounds (such as pollen), and works to destroy them.

• Immune-mediated

Immune-mediated reaction or disease: A condition or disease caused by abnormal activity of the immune system in which the body’s immune system either over-reacts (e.g., immune-mediated contact dermatitis) or starts attacking the body itself (e.g., autoimmune hemolytic anemia). See also autoimmune.

• Immunity

A condition in which the animal’s immune system has been primed and is able to protect the body from a disease-causing agent such as a certain virus or bacteria. An animal could have immunity to one agent, such as parvovirus, but not have immunity to another agent, such as rabies.

• Immunization

The process of rendering an animal protected (immune) against a certain disease. Vaccination is a way to produce immunization. However, just because an animal has been vaccinated (received a vaccine) does not necessarily mean the animal is immune. If the body did not correctly react to the vaccine or if the vaccine was defective, immunity would not occur. No vaccine produces immunity in 100% of the population to which it was given. ‘Vaccination’ is not the same as ‘immunization.’

• Immunodeficiency

Reduced function of the immune system of an animal, making it more susceptible to infectious disease. Can be an inherited defect or caused by drugs, radiation, or viruses.

• Immunostimulant

A compound which stimulates the immune system to work more effectively to kill bacteria, viruses, or cancer cells.

• Immunosuppressive

Something, for instance a drug, hormone, or virus, that reduces the function of the immune system of an animal. An animal with reduced function of its immune system is called ‘immunosuppressed.’

• Incontinence

The inability to control the excretion of wastes; generally used to describe the inability to control urination.

• Incubation period

The time between the exposure to a disease, causing agent, and the onset of signs of the disease.

• Infection

The invasion and replication of microorganisms in tissues of the body; generally causes disease or local inflammation.

• Infectious agents

The organisms that cause infection; can be viruses, bacteria, fungi, or parasites.

• Infestation

A term used to describe an invasion of parasites.

• Inflammation

A condition in which tissue reacts to injury and undergoes changes during the healing process. As an example, a toe with a sliver of wood in it would be inflamed and show the signs of inflammation which include redness, increased temperature, pain, swelling, and a loss of or disordered function. The toe is swollen, red, hot, painful, and the animal is reluctant to walk on that toe.

• Infusoria

Microscopic organisms which are cultured as a food for the fry of freshwater fish.

• Inherited

A trait passed from one generation to the next in the genes from each parent.

• Innate

A permanent characteristic that is present because of the genetic make-up of the animal.

• Insoluble carbohydrate

Also, insoluble fiber. Fiber that resists enzymatic digestion in the small intestine.

• Insulin

A hormone produced by the pancreas which is necessary for glucose to be able to enter the cells of the body and be used for energy.

• Insulin resistance

A condition in which the blood glucose level remains higher than it should at an insulin dosage of 2 units/pound of body weight per day in cats.

• Insulinoma

Insulin-producing tumor of the pancreas; the increased production and blood level of insulin resulting from these tumors can cause low blood sugar (hypoglycemia).

• Intermediate Host

In the life cycle of some parasites, the immature form of the parasite must pass through a different type of host (animal, insect, snail, etc.), called the intermediate host, before it can re-enter and infect the type of animal it came from. An example would be heartworms. The adult worm lives in the dog or cat. The immature form, laid by the adult heartworm, is taken up by the mosquito. The immature form develops within the mosquito, and is then reintroduced into another dog or cat where it develops into the mature adult and the cycle repeats itself. The intermediate host for heartworms, then, is the mosquito.

• Interstitial

Between parts or within the spaces of tissue.

• Intestine

The part of the digestive system extending from the stomach to the rectum; includes both the small and large intestines and functions in the absorption of water and nutrients; also called bowel or gut.

• Intracellular

An action taking place within a cell.

• Intracranial

Originating within the cranial (brain) cavity.

• Intramuscular

Into the muscle (IM).

• Intranasal

Into the nose.

• Intravenous

Into the bloodstream via a vein.

• Intussusception

A condition in which one part of the intestine ‘telescopes’ into another.

• Iris

The colored portion of the eye is called the iris. As with humans, dogs’ iris colors vary. In the center of the iris is the black opening called the pupil. This opening can be made larger or smaller by muscles called ciliary bodies, that attach to the colored iris, causing it to expand or contract.

• Isoflavone

An estrogen-like substance produced by pasture plants; a type of phytoestrogen.

J

• Jaundice

The condition in which there is a buildup of waste products in the body called bilirubin. Bilirubin is yellow in color, therefore, an animal with jaundice will have yellow gums, skin (often seen on the inside flap of the ear), and a yellowish cast to the ‘whites’ of the eyes. It can occur if a large number of red blood cells are destroyed, the liver is not functioning normally, or the bile ducts are blocked.

• Jejunum

The longest part of the small intestine extending from the duodenum to the ileum.

• Jill

A female ferret.

• Jugular

Referring to the neck; specifically, the large jugular veins that return blood from the head and neck to the heart.

K

• KCS

Keratoconjunctivitis sicca is the technical term for a condition also known as ‘dry eye.’ It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.

• Keratitis

Inflammation of the cornea of the eye; may be caused by infection, trauma, or an allergic reaction.

• Keratoconjunctivitis sicca

Keratoconjunctivitis sicca (KCS) is the technical term for a condition also known as ‘dry eye’. It occurs because of inadequate tear production. Symptoms include a thick, yellowish discharge from the eye.

• Keratolytic

Softens and loosens crusts and scales on the skin.

• Ketoacidosis

A life-threatening condition in which ketones, which result from the breakdown of fat for energy, accumulate in the bloodstream and the pH of the blood decreases.

• Killed vaccine

Vaccines which are made by taking the real, disease-causing viruses (or bacteria), killing them, and putting them into a liquid base. Compare with ‘modified live vaccine’ and ‘recombinant vaccine.’

• Kinetic skull

Having mobile joints between various parts of the skull, e.g., being able to unhinge the jaws. This allows the mouth of the animal, e.g., snake, to open wider so that it can eat large prey.

• Kit

A baby ferret.

L

• Lactating

Producing milk.

• Large intestine

The lower part of the intestinal tract, usually made up of the colon, cecum, and rectum. Bacteria that live harmlessly in the large intestine help to digest complex carbohydrates.

• Larva

The worm-like offspring of an insect (plural larvae).

• Larynx

The larynx is a muscular tube in the neck that allows air to pass from the throat to the trachea (windpipe). The larynx contains the vocal cords, which allow people and animals to make sounds. The larynx has cartilage that opens to allow air into the trachea.

• Latent

A dormant stage of disease; the patient is infected with an organism, but is not yet ill.

• Leukopenia

A condition in which the numbers of white blood cells in the blood are lower than normal.

• Lichenification

Thickening and hardening of the skin.

• Lipase

Digestive enzyme, produced by the pancreas, which breaks down fat.

• Liver

The largest organ in the abdomen, responsible for producing enzymes required for digestion of food, and bile that helps to digest fat. The liver also detoxifies the blood and may be damaged in the process.

• Low passage vaccine

A low passage vaccine contains virus particles which have been attenuated, or weakened, less than those in the ‘average’ vaccine. Low passage vaccines can generally elicit an immune system response in young animals who have a maternal antibody level that would prevent them from responding to an ‘average’ vaccine.

• Lymph nodes

Part of the immune system of an animal. Small masses of tissue that contain white blood cells called lymphocytes. Blood from the nearby area is filtered through the lymph node allowing foreign or infectious material to be recognized and destroyed if possible.

• Lymphocytes

The class of cells in the body which are responsible for mounting an immune response. Two main types are B cells and T cells.

• Lymphokines

Chemicals produced by T lymphocytes. Some lymphokines signal macrophages and other phagocytes to destroy foreign invaders.

M

• Macrophage

A type of phagocyte (cell in the body which ‘eats’ damaged cells and foreign substances such as virus and bacteria).

• Malabsorption syndrome

Maldigestion syndrome: A condition involving the intestine in which food may not be properly digested or the nutrients not absorbed.

• Malignant

A process that does harm to nearby tissues. Usually synonymous with cancer, a tumor that grows quickly and spreads into other tissues.

• Malnutrition

Ill health due to dietary deficiency or imbalance.

• Mammary

Pertaining to the breast.

• Mandible

Lower jaw.

• Mange

Any of several skin and ear conditions caused by a variety of mites.

• MAOIs

Monoamine oxidase inhibitors. Substances that inactivate the enzyme monoamine oxidase which regulates certain transmitter chemicals between nerves. These compounds include certain types of antidepressants and also insecticides containing amitraz (such as Mitaban and Preventic collars).

• Marsupial

An order of mammals including kangaroos, opossums, and sugar gliders in which the female has a pouch on the abdomen which holds the young and has nipples for the young to nurse.

• Mast cell tumor

A nodular growth, usually on the skin, which involves cells (mast cells) which contain large amounts of histamine and normally play a role in allergic reactions. All mast cell tumors in dogs should be considered potentially malignant.

• Masticate

Chew.

• Mastitis

An infection or inflammation of the mammary glands.

• Maternal antibody

Antibody in a newborn animal which the newborn acquired through the placenta or colostrum (the first milk).

• Meal

When referring to food ingredients, meal means a ground-up preparation. Chicken meal is ground up chicken, which might include bones and feathers. Meat meal means ground up muscle meat.

• Median survival time

Time at which 50% of the animals had died.

• Megacolon

A condition in which the colon enlarges and dilates, which results in feces accumulating in the colon. Constipation then occurs. This condition is more common in cats than dogs.

• Melena

Darkening of the stool due to the presence of digested blood, which indicates bleeding is occurring in the stomach and/or beginning of the small intestine. The feces generally look black and tarry.

• Memory

(Immunologic) Memory: When an animal mounts an immune response against a foreign substance, some cells are created to ‘remember’ the antigens on that substance. If the animal is again exposed to the substance, these cells will help the body respond much faster and to a higher degree.

• Metabolic acidosis

A condition in which the pH of the blood is too acidic because of the production of certain types of acids.

• Metabolize

To have molecules transformed within the body tissue through chemical processes.

• Metabolize energy (ME)

(ME) is the net energy available to an animal from a certain food.

• Metacarpus

The front limb between the carpus and the phalanges (toes).

• Metastasis

Spread of a tumor from its original location to a remote one, by tumor cells that are carried in the blood.

• Metatarsus

The part of the rear limb between the tarsus and the phalanges (toes).

• Methemoglobin

An altered hemoglobin which does not carry oxygen.

• Methemoglobinemia

A condition of the blood in which there are large amounts of methemoglobin which is an altered hemoglobin which does not carry oxygen.

• Microfilaremia

The presence of microfilariae in the blood.

• Microfilaria

The larval form of some parasitic worms, for example heartworms. These worms do not lay eggs, they produce microfilariae (plural of microfilaria) instead.

• Microfilaricide

Compound which kills microfilaria, the immature forms of heartworms which circulate in the blood.

• Microorganism

A single-celled life form that is invisible to the naked eye and that may cause disease in man or animals.

• Mineralization

The process in which minerals are laid down within tissue in an abnormal pattern causing a hardening of the tissue.

• Mineralocorticoids

Hormones produced by the adrenal gland which regulate the amounts of sodium, potassium, and chloride in the blood.

• Miticide

An agent that kills mites.

• Mitochondria

Parts of the cell which are responsible for providing the cell with energy.

• mL

Short for milliliter. A liquid measure, the same volume as a cc. 28 mL = 1 liquid oz.

• Modified live vaccine

Vaccines which are made by taking the real, disease-causing virus and altering (attenuating) it in a laboratory to a non-disease causing virus. Compare with ‘killed vaccine’ and ‘recombinant vaccine.’

• Monoamine oxidase inhibitor

(MAOI): Substances that inactivate the enzyme monoamine oxidase which regulates certain transmitter chemicals between nerves. These compounds include certain types of antidepressants and also insecticides containing amitraz (such as Mitaban and Preventic collars).

• Monovalent vaccine

A vaccine that is manufactured to stimulate the body to produce protection against only one disease, e.g., rabies vaccine. Compare with ‘multivalent vaccine.’

• Motility

Movement, e.g., intestinal motility is the muscular contractions of the intestines which move the food from the stomach to the anus.

• Mucolytic

Breaks down mucous.

• Mucopolysaccharide

A carbohydrate which also contains a hexosamine molecule and is a component of mucous.

• Mucosa

Specialized membrane which covers various passages and cavities exposed to the air such as the mouth, nose, inner portion of the eyelids, vagina. Examination of the mucous membranes can provide important information: if they are dry, the animal is likely dehydrated; pale, and the animal may be anemic or in shock; yellow, and the animal is said to jaundiced due to accumulation of waste products which should be eliminated by the liver. Mucous membranes.

• Mucous membranes

Specialized membrane which covers various passages and cavities exposed to the air such as the mouth, nose, inner portion of the eyelids, vagina. Examination of the mucous membranes can provide important information: if they are dry, the animal is likely dehydrated; pale, and the animal may be anemic or in shock; yellow, and the animal is said to be jaundiced due to accumulation of waste products which should be eliminated by the liver.

• Multivalent vaccine

A vaccine that combines two or more components to stimulate the body to produce protection against all the components. Most ‘distemper’ vaccines for puppies are of the multivalent type, and commonly include distemper, parvovirus, adenovirus cough, hepatitis, and parainfluenza. Compare with ‘monovalent’ vaccine.

• Musculoskeletal

Pertaining to the muscles and skeleton.

• Myasthenia gravis

Myasthenia gravis is a neuromuscular disease in which there is a failure of the nerves’ ability to stimulate and control the actions of certain muscles. See article: Myasthenia gravis in Puppies.

• Mycosis

Disease caused by a fungus such as blastomycosis, histoplasmosis, and ringworm.

• Mydriasis

Small pupil size.

• Myelogram

Radiograph (x-ray) of the spinal cord taken after a contrasting dye has been injected into the space around the spinal cord.

• Myocardium

The middle layer of heart muscle.

N

• Nauplii

Newly hatched brine shrimp.

• Nebulize

Convert into a fine spray form.

• Necropsy

Postmortem examination.

• Necrosis

The death and breakdown of cells.

• Nematodes

A common name for any roundworm of the phylum Nematoda.

• Neoplasia

Abnormal growth and accumulation of cells. Neoplasias may be benign or malignant.

• Nephropathy

Any disease or abnormal functioning of the kidney.

• Nephrotoxic

Destructive to kidney cells.

• Neuropathy

Abnormal functioning of nerves.

• Neurotransmitter

Chemical used as a messenger from one nerve cell to another.

• Neuter

Sterilization by surgical removal of the testicles of a male animal or ovaries of a female animal.

• Neutralize

To change from acidic or alkaline to a neutral pH.

• NIDDM

Non-insulin dependent diabetes mellitus (NIDDM): A type of diabetes mellitus in which although the blood glucose levels are higher than normal, they are not immediately life-threatening, and the animal can survive without supplemental insulin. Also called Type II diabetes.

• Nocturnal

Animals that are active during the night and sleep during the day.

• Nodule

Solid bump or lump in the skin that is over 1/3 inch in diameter.

• Non-steroidal anti-inflammatory

NSAIDS: Agents which reduce inflammation, but are not in the class of drugs known as steroids. Examples include aspirin, Rimadyl, and phenylbutazone.

• Noncore vaccine

Vaccine which should only be given to animals at increased risk of exposure to a disease, example, leptospirosis in dogs or feline leukemia in cats (see core vaccine).

• Nonpathogenic

Not causing disease. Some bacteria, such as those that normally live in an animal’s intestines, are nonpathogenic.

• Nonseptic

A condition not caused by an infection. For example, septic arthritis is caused by an infection with bacteria, yeast, or other agent; a case of nonseptic arthritis may be caused by injury or cancer.

• Nucleated erythrocytes

Immature form of red blood cells.

• Nutraceutical

A very broad term describing certain components in food (plant or animal) or nutritional supplements, which contain substances normally present in the body that aid in the proper functioning of body systems.

• Nutrient

Compounds in foods which are essential for life. Nutrients include protein, fats, vitamins, minerals, etc.

• Nystagmus

Constant involuntary movement of the eye, often from side to side.

O

• Obligate carnivore

An animal that requires in its diet nutrients that are found in sufficient quantities only in meat or other animal products.

• Obsessive compulsive

A behavioral condition in which a pet repeatedly performs an action out of context. It is thought that the behavior is an expression of stress, frustration and/or conflict. Certain breeds are more prone to these behaviors. The behaviors include tail-chasing, some cases of excessive barking, continual licking, and biting the air as if snapping at an invisible fly.

• Occult

Indicating a disease or condition that is clinically not apparent.

• Ocular

Relating to the eye.

• Off label

Term used to describe the use of a medication for a condition for which it was not FDA approved. A large number of medications used in veterinary medicine are used ‘off label.’ If veterinarians only used FDA approved medications, options for treatments of certain conditions would be severely limited or nonexistent. The safety and efficacy of off-label uses of medications is often determined in university research settings, but the manufacturer of the drug does submit the results or go through the elaborate FDA approval process.

• Offal

Animal organs rejected at slaughter as unfit for human consumption, e.g., spleen, intestine, brain, lungs.

• Omnivore

Animal that eats both flesh and plants.

• Opioid

Narcotic drug which has an activity similar to that of opium.

• Oral hypoglycemic

A medication, given by mouth, which lowers the level of glucose in the blood. Example: glipizide.

• Osmotic diuretic

A compound that increases the amount of urine formed and rids the body of excess fluid by being filtered through the kidney into the urine in concentrated amounts and carrying water with it.

• Osteomyelitis

An inflammation and infection of the bone.

• Otic

Pertaining to the ear.

• Ototoxic

Destructive to the structures of the ear.

• Over the counter

Can be purchased without a prescription, like aspirin and vitamins.

• Ovulate

The release of an egg from the ovary of the female.

• Oxidize

To combine with oxygen.

• Oxytocin

A hormone that stimulates milk flow in lactating mammals (females nursing their young), and contractions of the muscles of the reproductive tract in many species.

Back to top

P

• Packed cell volume

(PCV), hematocrit: A laboratory test to monitor the relative number of red blood cells present in the blood. A blood sample is placed in a tiny glass tube and spun in a centrifuge. The cells are heavier than the plasma and are compacted at one end of the tube. After the tube is spun, it is examined and the packed cell volume is determined as the percentage of the red cellular portion relative to the total amount of blood in the tube (i.e., remainder being the plasma). The normal for dogs is 40-59 and cats is 29-50.

• Palatable

Tasty; refers to food that is readily accepted.

• Palpation

To examine with the hands or fingers.

• Pancreatitis

Inflammation of the pancreas, a severe and sometimes life threatening disease often associated with eating fatty foods. Symptoms include vomiting and a painful abdomen.

• Pannus

A chronic condition of the eye in which blood vessels grow across the cornea (the clear surface of the eye). The cornea looks hazy and sometimes reddened; it may eventually take on a dark pigment. This condition is also called chronic superficial keratitis.

• Papule

Solid bump on the skin, less than 1/3 inch in diameter.

• Paralysis

Loss of motor function (movement) in a certain part of the body. Paralysis may be flaccid, in which muscles are weak and have little or no tone; or spastic, in which the muscles are tight.

• Parasiticide

Medication formulated to kill parasites.

• Parasympathetic

The portion of the nervous system which stimulates the pancreas to produce digestive enzymes and stimulates many of the smooth muscles in the body including those of the stomach and intestine. It also tends to slow the heart rate.

• Parenterally

A term used to describe the administration of a drug by means other than by mouth.

• Paresis

Slight or incomplete paralysis.

• Parthenogenesis

A form of reproduction in which the egg develops into a new individual without fertilization by sperm. Parthenogenesis has been observed in many lower animals, including some snails and insects.

• Parturition

The act of giving birth.

• Passive immunity

Immunity produced by providing an animal with antibodies or immunologic cells from another source, such as colostrum. Compare with ‘active immunity.’

• Pathogenic

Causing disease.

• Pathologist

A specialist in veterinary medicine who examines the changes in body tissues and organs caused by disease.

• PCV

Packed cell volume. PCV, hematocrit: A laboratory test to monitor the relative number of red blood cells present in the blood. A blood sample is placed in a tiny glass tube and spun in a centrifuge. The cells are heavier than the plasma and are compacted at one end of the tube. After the tube is spun, it is examined and the packed cell volume is determined as the percentage of the red cellular portion relative to the total amount of blood in the tube (i.e., remainder being the plasma). The normal for dogs is 40-59 and cats is 29-50.

• Pediculosis

An infestation of lice.

• Penicillinase

An enzyme produced by some bacteria which inactivates certain types of penicillin thus making the bacteria resistant to them.

• Perianal fistula

A deep infection around the anus which often results in ulcers and deep draining tracts, most commonly seen in German Shepherds.

• Perineal

The area between the anus and the genital organs.

• Peritoneal dialysis

A process used to remove waste products from the body. Electrolyte fluids are administered into the abdomen, waste products of the body enter the fluids, and then the fluids are removed.

• Peritoneum

The membrane lining the wall of the abdominal cavity.

• Peritonitis

Inflammation of the lining of the abdomen.

• Phagocyte

Cell in the body which ‘eats’ damaged cells and foreign substances such as virus and bacteria. A macrophage is a type of phagocyte.

• Phalanges

Toes.

• Pheromone

Chemical secreted by an animal and sensed by another animal of the same species, and often causing behavior change in that animal.

• Photoperiod

The number of hours of light per 24-hour period.

• Photosensitivity

A condition in which the skin reacts abnormally to light, especially ultraviolet light or sunlight. It is usually caused by the interaction of light with certain chemicals in the skin such as antibiotics, other medications, hormones, or toxins.

• Phytochemical

Substances in plants which affect a body system and may promote health and decrease the risk of a disease such as cancer.

• Phytoestrogen

Substances which have an activity similar to estrogens and are produced by plants.

• Pica

Craving to eat unnatural articles such as rocks or dirt.

• Placebo

A substance which is given that has no therapeutic value; often called a ‘dummy pill’ or ‘sugar pill.’ Often given to half of the patients in a trial of a new drug, to better assess the effectiveness of the new drug.

• Plantigrade stance

Standing and walking with the hocks on or almost touching the floor.

• Plaque

A build-up of bacteria, saliva, and food on the teeth. See also Tartar.

• Plastron

The lower hard shell-like structure which protects the abdomen of a turtle or tortoise.

• Platelets

Cellular components found in the blood which help clots to form. In the body, microscopically small vessels often break in the normal course of events. Platelets and a protein called fibrinogen ‘plug’ the break in the vessel and prevent blood from leaking out.

• Polyarthritis

Arthritis which involves two or more joints.

• Polydactyl

The presence of extra toes.

• Polydipsia

Excessive thirst resulting in excessive drinking.

• Polyestrous

During one sexual season, continuing to come into heat if not bred. Cats are polyestrous, dogs are not.

• Polyp

A small growth from mucous membranes such as those lining the nasal cavity and intestinal tract.

• Polyphagia

Excessive ingestion of food.

• Polyuria

Excessive urination.

• Posterior

Positioned in back of another body part, or towards the rear half of the animal. Opposite of anterior.

• Postoperative

After surgery.

• Prepuce

The sheath of skin which covers the penis.

• Proestrus

The stage of the estrus cycle, right before an animal comes into heat.

• Progesterone

A hormone produced by the ovaries which is responsible for the continuation of pregnancy.

• Prognosis

The forecasted outcome and recovery.

• Prolactin

Hormone secreted by the pituitary gland that stimulates the growth of mammary tissue and the production of milk.

• Prolapsed rectum

Because of irritation or injury, the inner part of the rectum is pushed out so that it is visible as a pink mass protruding from the anal opening.

• Prostaglandin

Several types of chemicals made by cells which have specific functions such as controlling body temperature, stimulating smooth muscle, and influencing heat cycles.

• Protease

Enzyme which breaks down protein.

• Protozoans

Single-celled animals invisible to the naked eye. Most are free living and a few are parasites in animals or man.

• Pruritus

Itching.

• Psittacine

Birds that belong to the order Psittaciformes. Common psittacines include budgies, cockatiels, lories, cockatoos, conures, amazons, African greys, lovebirds, senegals, and jardines.

• Pulmonary

Relating to the lungs.

• Pulmonary arteries

The large vessels leading from the heart to the lungs.

• Pulmonary edema

Fluid accumulation in the lungs.

• Pulmonary emboli

Pulmonary embolism: Blood clot that travels to the blood vessels in the lung and obstructs them.

• Pupa

A dormant form of an insect (plural pupae). A larva spins a cocoon to protect itself, and becomes a pupa. The pupa does not feed, but gradually changes form and becomes a new adult.

• Pustule

Small elevated area on the skin filled with pus.

• Pyloroduodenal

An obstruction in the area where the stomach and small intestine meet.

• Pyoderma

An infection of the skin; usually the result of a bacterial invasion.

• Pyometra

An infection of the uterus.

Q

• Queen

A female cat used for breeding.

• Queening

In cats, the act of giving birth.

R

• Rabies

A fatal virus disease of warm blooded animals including man, that affects the brain and is spread in the saliva of infected animals. Rabid animals have a temperament change. Wild creatures become bold enough to attack human beings, and docile domestic animals may turn on their owners.

• Radiology

X-ray.

• Reagent grade

A compound with the purity and quality that allows it to be used in a laboratory.

• Recombinant vaccine

There are certain antigens on viruses and bacteria which are better at stimulating an antibody response by the animal than others. The genes for these antigens can be isolated, and made to produce large quantities of the antigens they code for. A recombinant vaccine contains these antigens, not the whole organism. Compare with ‘modified live vaccine’ and ‘killed vaccine.’

• Recumbency

Lying down.

• Reflex ovulator

Only ovulating after being bred. Cats are reflex ovulators, dogs are not.

• Regulation

Using insulin to maintain the blood glucose level of an animal within the acceptable range.

• Regurgitation

Expelling food from the esophagus.

• Renal

Pertaining to the kidneys.

• Renal insufficiency

The decreased ability of the kidneys to rid the body of wastes.

• Resistance

A term used to describe bacteria which have mutated or changed so they are not affected by an antibiotic that previously killed them or slowed their growth. As more bacteria become resistant to various antibiotics, there are fewer antibiotics which will have an effect on them, thus newer and stronger antibiotics will need to be developed. Inappropriate use of antibiotics (using them too often, for too short a duration or in insufficient dose) may promote the development of resistance.

• Resorption

In pregnancy, a condition in which the fetus dies, and instead of being aborted, the fetal tissue dissolves within the uterus and is absorbed by the mother. The mother will show no outward signs of a fetal resorption.

• Respiratory

Relating to breathing or the lungs.

• Respiratory depression

Decrease in the rate or depth of respiration.

• Retina

The rear interior surface of the eyeball is called the retina. The retina contains nerve cells referred to as rods and cones. The rods are sensitive to light and the cones to color. The retina receives the light and color and converts them into nerve impulses which go to the brain.

• Ringworm

A type of fungal infection of the skin. See article: Ringworm in Dogs and Cats.

S

• Scale

Accumulation of loose fragments of the top layer of the skin.

• Schiff-Scherrington posture

A condition, caused by a lesion in the spinal cord, in which the front legs are held rigid and straight, and the rear legs are weak or paralyzed. Sometimes, the neck may be hyperextended, with the head held up and over the back.

• Sclerosis

A hardening of tissue, usually the result of chronic inflammation.

• Scute

In turtles and tortoises, the plates which cover the bony portion of the shell. In snakes, the larger, thicker scales on the underside of the body which provide support, protection, and traction.

• Sebaceous adenitis

Inflammation of a sebaceous (oil-producing) gland. In dogs, sebaceous glands are found on the top of the tail near its base, and at the junction of mucous membranes with skin. In cats, these glands are found on the chin, lip margins, and the top of the tail.

• Sebaceous gland

A gland in the skin which produces an oily substance.

• Second generation

A description of medications developed from an earlier form of the medication. First generation medications were developed from the original form of the drug; second generation medications are adaptations of first generation drugs; third generation drugs are adaptations of second generation, etc.

• Secondary infection

Infection which occurs because the tissue and its natural defenses have been damaged by another condition.

• Secondary response

The faster and greater immune response produced by an animal who has previously encountered that specific antigen. Memory cells are responsible for this more efficient response. Also called ‘anamnestic response.’

• Seizure threshold

The level of stimulation at which a seizure is produced. Raising the seizure threshold makes it less likely a seizure will occur.

• Selective serotonin reuptake inhibitor

(SSRIs), Selective serotonin reuptake inhibitors: Medications which slow down the ability of nerve cells to absorb serotonin, a neurotransmitter (chemical that serves as a messenger between nerves). Example: Prozac.

• Separation anxiety

A behavioral condition in which the pet becomes anxious when separated from the owner. Dogs with separation anxiety tend to ‘shadow’ their owners, greet them exuberantly when they return after being gone, and sometimes vocalize, chew destructively, and urinate or defecate when separated from their owners.

• Sepsis

The presence of toxins in the blood or other tissues; the toxins are produced by bacteria or other microorganisms.

• Septic

A condition caused by an infection e.g., with bacteria or fungi, or toxins they produce.

• Septicemia

A disease affecting many organ systems due to toxins in the blood which are released by bacteria or other microorganisms. Signs include fever, pinpoint bruises on mucous membranes, and lesions in the joints, heart valves, eyes, or other organs.

• Serology

Laboratory testing for antibody-antigen reactions and antibody levels.

• Serotype

A subdivision of a species of microorganism, e.g., a bacteria, based upon its particular antigens.

• Serous

Thin and watery.

• Serum

The fluid portion of the blood after it has clotted and the cells have been removed.

• Shedding

Shedding (of organisms): A term used to describe the release of organisms (bacteria, protozoa, viruses) into the environment from an infected animal. The organisms may be in the stool, urine, respiratory secretions, or vaginal discharges. The ‘shedding’ animal may or may not be showing symptoms of disease.

• Skin cytology

Examination, with a microscope, of a skin scraping or material from swabbing the skin. The material may be stained and checked for the presence of yeast, bacteria, tumor cells, etc.

• Skin scraping

Scraping some material from the surface of the skin and looking at it under a microscope, e.g., to check for skin mites.

• Smooth muscle

The type of muscle found in the internal organs such as stomach and intestines (not the heart).

• Soluble carbohydrate

Also, soluble fiber. Easily digested carbohydrates like starch.

• Somnolence

Sleepiness, a condition of semiconsciousness approaching coma.

• Somogyi effect

A condition in which the blood glucose level increases if too much insulin is given. It occurs when insulin causes the blood glucose level to go so low it stimulates the production of other hormones in the body such as epinephrine, which promote the breakdown of glycogen (the chemical compound which the body uses to store glucose) and increases the blood glucose level above normal. It is also called rebound hyperglycemia or insulin-induced hyperglycemia.

• Spay

Sterilization by surgical removal of the ovaries and uterus of a female animal.

• Sphincter

A ring-like band of muscle that constricts a passage or closes an opening, e.g., the anal sphincter constricts to close the anus and relaxes when the animal is passing stool. The urethral sphincter closes the urinary bladder.

• Spirochete

A type of bacteria which is long, slender, and assumes a spiral shape. Leptospira species and the bacteria that causes Lyme disease (Borrelia burgdorferi) are spirochetes.

• Spleen

Part of the immune system of an animal. A large, tongue-shaped organ in the abdomen containing many lymphocytes. The spleen filters blood and removes damaged cells. It can also manufacture new blood cells if the animal’s bone marrow is damaged.

• Squamate

Scaly-bodied reptile including lizards and snakes.

• SSRI

Selective serotonin reuptake inhibitors: Medications which slow down the ability of nerve cells to absorb serotonin, a neurotransmitter (chemical that serves as a messenger between nerves). Example: Prozac.

• Stasis

In the gastrointestinal tract, a condition in which the food does not move through normally, but remains in one section, e.g., food does not pass from the stomach into the intestine.

• Status epilepticus

A condition in which the animal exhibits one severe (Grand Mal) seizure right after another, with no time to recover in-between.

• Stenosis

The narrowing of an organ of passage such as a blood vessel or intestine.

• Stress-induced hyperglycemia

A condition in cats in which the blood glucose level becomes abnormally high when the animal is stressed, e.g., in the veterinarian’s office.

• Stricture

The narrowing of an organ of passage such as a blood vessel or intestine.

• Struvite

A chemical compound, magnesium ammonium phosphate, which is made by the body and can form crystals and stones in the urinary bladder.

• Subcutaneous

Under the skin; often called ‘sub Q.’

• Subluxation

A partial dislocation of a joint in which thebones become out of alignment, but the joint itself is still intact.

• Substrate

Relative to the husbandry of reptiles, amphibians, and small mammals, the substrate is the material that lines the bottom of a cage.

• Sulfonamides

A class of antibiotics which contain sulfur. They are bacteriostatic (they stop the growth (reproduction) of bacteria, but do NOT kill them).

• Superfecundation

Having a litter with more than one father (or breeding).

• Supraventricular tachycardia

A condition in which the heart beats very rapidly because of signals coming from the atria (chambers of the heart that receive the blood) or near the junction of the atria with the ventricles (the chambers of the heart that pump the blood to the body or lungs).

• Sympathomimetic

Producing effects similar to the ‘flight or fight’ response, which means the body is alerted to a danger of some sort and prepares to basically run or fight. Sympathomimetic effects include increased heart rate, sweating, and increased blood pressure.

• Syncope

The temporary loss of consciousness; fainting.

• Synergist

An agent that enhances the action of another.

• Synovial

Pertaining to a joint made up of bone ends covered with cartilage, ligaments, a cavity filled with synovial fluid (joint fluid) and an outside fibrous capsule, e.g., hip joint, elbow joint.

• Systemic

Throughout the body.

T

• T cell

Also called ‘T lymphocytes.’ The type of lymphocyte which is responsible for cell-mediated immunity. T cells may directly kill a cell or produce chemicals called lymphokines that activate macrophages which will kill the cell.

• Tachycardia

An abnormally high heart rate.

• Tachypnea

Rapid breathing.

• Tarsus

The ankle (rear leg) of dogs and cats; also called the hock.

• Tartar

A build-up of bacteria, saliva, and food on the teeth which becomes mineralized, forming a hard coating and eventually causing gum disease and tooth loss. See also ‘Plaque.’

• Temporomandibular joint

The joint between the lower jaw and the skull.

• Third generation

A description of medications developed from an earlier form of the medication. First generation medications were developed from the original form of the drug; second generation medications are adaptations of first generation drugs; third generation drugs are adaptations of second generation, etc.

• Thrombocytopenia

A lower than normal number of platelets in the blood. Platelets, which are actually fragments of specific types of cells, are necessary for blood to clot. Signs of thrombocytopenia include bruising and bleeding from the nose, into the gastrointestinal tract, etc.

• Thyrotropin releasing hormone

Hormone produced by the hypothalamus that stimulates the pituitary gland to produce thyrotropin (thyroid stimulating hormone-TSH), which in turn stimulates the thyroid gland to produce thyroid hormone. Also called TSH releasing factor or TSH releasing hormone.

• Tissue

A group of specialized cells that together perform a particular function, e.g., muscle tissue, nerve tissue, bone.

• Titer

A measurement of the amount of antibodies in the blood. The test to measure antibodies is usually performed by making a number of dilutions of the blood and then measuring at what dilution there is sufficient antibody to react in the test. For example, a titer of 1:8 (one to eight) means the blood can be diluted to one part blood and seven parts saline and still produce a positive reaction in the test. The higher the titer (1:16 is higher than 1:8), the more antibody is present. (NOTE: The word ‘titer’ may also be used when discussing the amount of antigen present, e.g., a high titer vaccine has a large number of virus particles.)

• Topical

To be used on the skin.

• Torsion

The twisting of an organ.

• Toxemia

A condition in which toxins move into the bloodstream.

• Tracheobronchitis

Inflammation of the trachea and bronchi.

• Transient

Temporary.

• Transport host

An animal or insect which carries an immature parasite from one mammalian host to another.

• Tricyclic antidepressant

A class of antidepressants which work by decreasing the amount of certain chemical transmitters taken up by specific nerve cells. The tricyclic antidepressants include clomipramine, amitriptyline, and nortryptyline and are often used to treat behavioral problems in small animals.

• Tubule

Microscopic ducts. The tubules in the kidneys help to concentrate the urine.

• Tumor

Abnormal growth or swelling; term often used to designate cancer.

• Type I diabetes

A form of diabetes in which so little insulin is produced that supplemental insulin must be given for the animal to live. Also called insulin dependent diabetes mellitus (IDDM).

• Type II diabetes

A type of diabetes mellitus in which although the blood glucose levels are higher than normal, they are not immediately life-threatening, and the animal can survive without supplemental insulin. Also called non-insulin dependent diabetes mellitus (NIDDM).

U

• Ulcer

A lesion in which the tissue surface is eroded away.

• Ultrasound

Ultrasound/ultrasonography: A technique used to get the image of a deep structure within the body by directing ultrasound waves at it and recording the reflections (echoes) from it.

• Umbilicus

The area of the body where the umbilical cord is attached; the belly button.

• Urate

A chemical compound which contains uric acid and is made by the body, and can form crystals and stones in the urinary bladder. Uric acid is a waste product from the breakdown of certain proteins.

• Urea

Wasteproduct of protein metabolism that is removed from the body by the kidneys.

• Urease

An enzyme that breaks down urea. Urea is a wasteproduct of protein metabolism that is removed from the body by the kidneys.

• Urinary incontinence

A phrase used to describe the inability to control urination.

• Urinary obstruction

A blockage in the urinary system, most often occurring in the urethra, the tube that leads from the urinary bladder to the outside of the body.

• Urinary retention

A condition in which the urinary bladder does not rid itself of all urine it contains during the process of urination.

• Urticaria

Hives; development of small swellings which may itch; usually caused by an allergic reaction.

• USP

United States Pharmacopeia – a drug regulating agency.

• Uveitis

Inflammation of the eye.

V

• Vaccination

The act of giving a vaccine. See also ‘immunization,’ since the two words have different meanings and are often confused.

• Vaccine failure

A term often used to describe a condition in which an animal who was vaccinated against a disease still gets the disease. In truth, there is usually nothing wrong with the vaccine, but for some reason, the animal’s immune system did not adequately react to it.

• Vasculitis

Inflammation of blood vessels.

• Vasoconstriction

A decrease in the diameter of blood vessels.

• Vasodilator

Agent which dilates, or increases the diameter of blood vessels.

• Vena cava

Either of two large veins carrying blood to the right atrium of the heart. The cranial vena cava brings blood from the head region, front legs, and upper chest to the heart; the caudal (or posterior) vena cava carries blood from the areas of the abdomen and hind legs to the heart.

• Vent

The outside opening of the cloaca, which is a common passageway for feces, urine, and reproduction.

• Ventricle

The chambers of the heart that pump the blood to the body or lungs.

• Ventricular arrhythmia

A heart condition in which the heart beats irregularly and/or at an abnormal rate because of signals coming from the ventricles (chambers of the heart that pump the blood).

• Vertebrate

Animal with a vertebral column (spine); includes such animals as fish, birds, turtles, reptiles, amphibians, and mammals.

• Vesicle

Small elevated area on the skin filled with a clear fluid.

• Vestibular system

Portions of the inner ear, nerves, and brain which help the body maintain balance.

• Villi

Microscopic projections which cover the intestine, greatly increasing the surface area and therefore, increasing the ability to absorb nutrients. Singular: Villus.

• Virus

The smallest form of life, invisible with an ordinary microscope. An infectious unit that enters and uses cells of plants or animals for replication. Some viruses cause disease in animals or plants.

• Viscerocutaneous

Pertaining to the internal organs and skin.

• Viscosity

Thickness of a fluid, e.g., molasses is more viscous than water.

• Vital signs

The signs of life which are pulse, respiration, and temperature.

• Volvulus

Twisting of the stomach or intestine, which often has the effect of cutting off the blood supply to it.

• Vomeronasal organ

Sensory organ also called ‘Jacobson’s organ,’ which detects pheromones.

W

• Warm-blooded

Having a relatively high body temperature that is regulated internally and is independent of the environmental temperature. Mammals and birds are warm-blooded.

• Wart

Benign growth caused by a virus.

• Wasting

Loss of muscle mass due to decreased food intake or increased metabolic rate.

• Whelping

In dogs, the act of giving birth.

• White blood cells

Cells in the blood whose major role is to defend the body against invading organisms such as bacteria, viruses, and fungi. There are different types of leukocytes: lymphocytes are part of the immune system; monocytes, eosinophils, and neutrophils eat or engulf organisms; basophils contain histamine and are involved in inflammatory reactions.

• Window of susceptibility

A time period in the life of a young animal in which the maternal antibodies are too low to provide protection against a certain disease, but too high to allow a vaccine to work and produce immunity.

Z

• Zoonotic

A disease which can be transmitted between animals and people.

 

TERMINOLOGY USED IN ANIMAL HUSBANDRY

VETERINARY GLOSSARY

Compiled  & Shared by- Team, LITD (Livestock Institute of Training & Development)

Image-Courtesy-Google

Reference-On Request.