Postmortem Techniques in Poultry

Postmortem Techniques in Poultry

Shruti Shaurya

M.V.Sc. Scholar, Division of Medicine, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh-243122.

 The term postmortem originates from a Latin word which means after death. A post-mortem (PM) is a specialized procedure conducted following death to ascertain the cause of death. This process demands a thorough understanding of animal anatomy. The practitioner must be familiar with the appearance of normal, healthy tissue, a skill acquired through hands-on experience rather than from textbooks. An accurate diagnosis of poultry diseases relies on three crucial elements: 1. A systematic strategy for inspecting the bird’s body. 2. Recognizing vital organs and body structure. 3. Acquiring knowledge about disease symptoms and lesions.

Obtaining a prompt diagnosis is highly significant. There are two distinct problem categories that warrant investigation: 1. PM-based, laboratory-confirmed issues – these are straightforward problems that can be easily diagnosed, leading to appropriate treatment. 2. ‘In-depth’ problems requiring thorough investigation – these involve uncovering the root cause of infectious diseases, characterized by their vague and multifactorial nature. The goal is to determine the origin. The investigation of diseases associated with both mortality and morbidity includes examining case/flock history, conducting post-mortem examinations, and typically involving laboratory investigations.

The optimal method is to initiate the process with a review of medical history.

Mass History:

Poultry diseases should be viewed as ailments affecting the entire flock rather than individual birds. Prevailing symptoms in a few individuals typically indicate a more widespread issue within the flock. It is crucial to accurately document the flock’s history, as many diseases’ origins can be identified through this record.

• Commence recording history from the office, noting mortality, egg production, hatch rates, etc.
• Observe the farmhouse quietly.
• Engage with individuals involved by asking questions. A comprehensive flock history encompasses the following:
• Owner’s name and address.
• Flock size.
• Bird breed, strain, and age. Management information includes:
• Hatchery source.
• Type of operation.
• Feeding program.
• Complete vaccination history. Information regarding illness includes:
• Date of illness observation.
• Severity and the number of affected birds.
• Number of bird fatalities.
• Medication history.
• Previous flock disease outcomes and any unusual problems or conditions should also be included in the record.

 A structured approach to inspecting the bird’s body during a post-mortem examination: Conducting a post-mortem examination, also known as a necropsy, is a crucial process in veterinary medicine and pathology to determine the cause of death in animals.

Equipements Required: Conducting a post-mortem examination requires specific equipment to ensure a thorough and precise analysis. The use of sterile and appropriate instruments, along with careful documentation, ensures the reliability of findings during the examination process. Here is a list of essential tools and instruments:

1. Personal Protective Equipment (PPE):
   • Disposable gloves
   • Apron or gown
   • Face shield or goggles
   • Surgical mask
2. Dissection Instruments:
   • Scalpel or autopsy knife
   • Scissors (straight and curved)
   • Forceps (tissue and dressing forceps)
   • Probe or spatula
   • Rib shears or bone-cutting forceps
   • Bone saw
3. Specimen Collection and Storage:
   • Sterile containers for tissue samples
   • Specimen bags or jars
   • Labels for proper sample identification
   • Ice packs or a cooler for preserving samples during transportation
4. Measurement Tools:
   • Ruler or calipers for measuring lesions or abnormalities
   • Scales for weighing organs
5. External Examination:
   • Camera for documenting external findings
   • Notebook and pen for recording observations
   • Body bag or shroud for handling and transporting the carcass
6. Opening the Body:
   • Post-mortem table or dissection board
   • Scissors or rib shears for cutting through the chest and abdomen
   • Scalpel for making incisions
7. Organ Examination:
   • Disposable plastic trays or bowls for organ inspection
   • Organ hooks or probes for manipulation
   • Towels or absorbent material for keeping the area clean
   • Dissection guide or anatomy reference materials
8. Cleaning and Disposal:
   • Disinfectant solutions for cleaning instruments and the examination area
   • Biohazard bags for disposal of contaminated materials
9. Lighting:
   • Adequate overhead lighting or portable lamps to illuminate the examination area
10. Documentation:
    • Camera or smartphone for photographing external and internal findings
    • Notebooks or digital devices for recording observations and measurements
11. Sample Collection:
    • Sterile swabs for microbiological samples
    • Specimen tubes for storing and transporting samples
    • Containers with preservatives for toxicology samples
12. Histopathology and Laboratory Analysis:
    • Specimen containers with formalin for histopathological samples
    • Proper packaging materials for sending samples to a pathology laboratory

NECROPSY PROCEDURE

1. Preparation:Begin by ensuring that the examination area is clean, well-equipped, and adequately lit. Gather all necessary tools and equipment, including dissection instruments, specimen containers, and personal protective gear.
2. Record Keeping:Before starting the post-mortem examination, record essential information such as the identification of birds, including metallic tag numbers on the right and left wings or legs, any color marks on feathers, age, sex, breed, color, and the nutritional status of the birds. Immerse the carcass in water and place it on the necropsy table.
3. External Examination:Conduct an external examination of the bird, inspecting both the dorsal and ventral aspects of the skin. Stretch the feathers to check for ectoparasites, lesions, and injuries.
4. Opening the Body:

• Position the bird on its back with wings and legs extended. Abduct the legs
• by cutting the skin between the leg and the abdomen on each side, breaking open the hip joints, and dislocating the head of each femur from the acetabulum.
• Transversely cut the skin between the keel and the vent and peel off the skin over the abdomen and legs.
• Examine the muscles of the thigh and sternum.
• Incise the abdominal wall transversely between the keel and the vent, remove the sternum by cutting through the ribs, and clip the coracoid and clavicles with a bone cutter.
• Open the mouth by cutting through one corner (preferably the right side) and continue the incision through the pharynx and esophagus to open the crop.
• Remove the stomach and intestine in one piece after cutting through the esophagus just anterior to the proventriculus and at the cloaca.

5. Organ Examination:

• Examine the organs beneath.
• Remove different visceral organs separately, such as the liver, spleen, kidneys, etc., and examine them.
• Examine the surface of each visceral organ and make incisions for the examination of cut surfaces.
• Expose the nasal cavity by cutting the beak transversely near its attachment with the skin. Use the pointed end of the scissors to incise through the opening on either side to expose the infraorbital sinus and examine any abnormalities.
• Open the trachea along its entire length.
• Use blunt dissection to free the lungs from the thoracic wall and cut through the dorsal attachment.
• Expose the brachial plexus and sciatic nerve on both sides.
• Open and examine the major joints.
• Examine the brain by cutting and reflecting the skin over the skull and upper mandible. Carefully cut the skull and lift it to expose the brain.

6. Sample Collection:Collect representative samples of organs and tissues for further analysis. Use sterile instruments to obtain samples and place them in suitable containers with proper labeling. Samples may include tissues for histopathology, microbiology, and toxicology.
7. Histopathology:Submit tissue samples to a pathology laboratory for histopathological examination. Histopathology involves the microscopic analysis of tissues to identify cellular changes and abnormalities that may not be visible during the gross examination.
8. Microbiology:If infectious diseases are suspected, collect samples for microbiological analysis. This involves identifying and isolating microorganisms that may be responsible for the observed pathology. Properly label and transport samples to the appropriate laboratory.
9. Toxicology:In cases of suspected poisoning, collect samples for toxicological analysis. This helps identify any toxic substances or chemicals that may have contributed to the animal’s death. Follow specific protocols for sample collection and transportation.
10. Final Report:Compile all findings, including external and internal examinations, organ pathology, and laboratory results, into a comprehensive post-mortem report. The report should provide a clear and detailed account of the examination and its conclusions.

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