Fluid Therapy in Veterinary Practice

Dr Trupti Suryakant Kattimani ¹ and Dr Annarao ²

Veterinary officer, veterinary dispensary Salagar Basantpur, TQ:  Chincholi, Dist Kalaburgi

Senior veterinary officer, Veterinary Hospital, Kalagi, TQ: Kalagi, Dist: Kalaburgi

State: Karnataka, India

Water is the essential component of life, total water content of body constitutes 60 per cent of body weight, among this two third consist of intracellular fluid and one third consist of extracellular fluid. Total intake of water including food and water 45-60 ml/kg/day. Body metabolism activity produces 4-6 ml /kg/day. Output of fluid from body in terms of urine output 25-50 ml/kg/day and insensible loss in the form water vapours about 25 ml/kg/day. Acute fluid loss causes circulatory shock where as chronic fluid loss causes dehydration. Fluid balance will be disturbed whenever there will be disturbances in homeostasis in the body due to various pathological conditions.

Indications of fluid therapy are

1. Dehydration
2. Burn, injuries
3. Shock
4. Vomition
5. Diarrhoea
6. Blood loss from surgical procedures
7. Infectious diseases
8. Cold injury or frost bite
9. Trauma
10. Neoplasia
11. Corrections of acid-base balance and electrolyte disorders
12. Maintenance of tissue perfusion

Fluid therapy is defined as the administration of fluids to a patient as a treatment or preventive measure. Fluid therapy will be essential in above mentioned clinical conditions where there will be severe disturbances in fluid and electrolyte imbalance. Fluid therapy is necessary to maintain the homeostasis and for the recovery from the disturbances

Type of dehydration	Amount of fluid to be recommended	Frequency of fluid therapy
Mild (≤ 5 %)	25 ml/kg	Daily once
Moderate (up to 5 %)	50 ml/kg	twice
Severe (up to  10 %)	75 ml/kg	Thrice
Very severe (more than 12 %)	100 ml/kg	Continuous

 

The fluids are classified into crystalloids and colloids

Crystalloids

These are the aqueous solution composed of electrolyte, glucose and water. Crystalloids having lower molecular weight, are used as carrier for medication. Crystalloids are again classified into hypotonic, isotonic and hypertonic based on their osmolality compared to the blood plasma. Crystalloids containing acetate, lactate, gluconate converts into bicarbonate in liver and helps in equilibrium of Ph of blood, so they act as buffers. Crystalloids which contain all electrolytes like plasma are termed as balanced fluids. Crystalloids again classified into acidifying agents and alkalinizing agents based on their activity in the body. Alkalinizing agents includes Ringer’s lactate and sodium bi carbonate solution. Acidifying agents includes Normal saline.

Hypotonic crystalloids are the fluids which has an osmolality lower than that of blood plasma they are used in maintaining the fluid requirement and drug administration.

Ex: Dextrose 5 %, 0.45 % Sodium chloride

Isotonic crystalloidsare the fluids which has an osmolality equal to that of blood plasma they contain electrolyte and organic anions. Isotonic crystalloid solutions such as RL are often balanced one.

Ex: Ringer’s lactate, 0.9 % DNS

Hypertonic crystalloids are the fluid which has an osmolality higher than that of blood plasma.

Ex: 7.2 % NS, D 25 %

Crystalloids also classified as replacement fluids and maintenance fluids

Replacement fluids are the one which are used to replace the fluid loss from the body due to various patho-physiological conditions. Replacement fluids are isotonic. 20-25 % of replacement fluids remain within iv after one hour of infusion. Ex : 0.9 % NS, Ringers lactate

Maintenance fluids are the one used to maintain the body water and electrolyte deficit. Maintenance fluids are isotonic. Only 10 % of maintenance fluids remain in iv after one hour of infusion. Ex : 0.45 % NS

 

List of commonly used crystalloid solution and their clinical usage

S No	Fluids	Clinical indications
1	0.45 % Normal saline	Cardiac and liver disease
2	0.9 % Normal saline	Renal failure, hypercalcemia, hyperkalemia, alkalaemia
3	3 % Saline	Hypovolumeia, septic shock, endotaxaemia
4	7 % Saline	Shock, toxaemia
5	Dextrose normal saline	Dehydration Vomition Heat stroke mild diarrhoea
6	Ringer’s lactate	Dehydration, acidosis, acute blood loss, metabolic acidosis
7	Dextrose 5 %	Starvation, sepsis, hypernatremia
8	Dextrose 10 %	Ketosis, hypoglycemia
9	Sodium bicarbonate 1.3 %	Mild carbohydrate acidosis, acidosis
10	Sodium bicarbonate 5 %	Acute carbohydrate engorgement
11	Rintose/Intalyte®	Starvation, hypoglycemia, toxaemia

 

Colloid solutions

These are the type of fluids in which larger molecular weight particles such as proteins or carbohydrates suspended in crystalloid solutions. Basically they are used as plasma volume expandors. Colloids again classified into natural and synthetic based on their source of origin. Colloids replace intravascular fluid deficit, so colloids with crystalloids will be better for the correction of both intravascular and extravascular fluid deficit, combination therapy will reduce the crystalloid requirement by 25 to 50 %. Natural colloids are the protein containing substances such as plasma, whole blood and albumin solutions. They are used in clinical conditions like severe anaemia, hypoproteinaemia, emaciation and other clinical conditions. Synthetic colloids  includes larger molecular weight complex polysaccharides including dextrans, gelatins and polysaccharides. They are used in wide variety of clinical conditions. If we given one ml of colloidal solution 1-1.5 ml of vascular volume increases.

Rehydration formula of fluid therapy

ml of fluid needed for replacement= %dehydration × body wieght (kg)× 1000ml/kg

 

 

List of commonly colloidal solution and their clinical usage

S No	Fluids	Clinical indications
1	Heta starch	Hypovolemic shock
2	6 % Dextran	Hypoproteinaemia,
3	10 % Dextran	Edema, hypovolumic shock
4	Haemaccel	Gastritis, gastro-enteritis, shock
5	Mannitol	Cerebral edema
6	Amino acid solution	Starvation, emaciation, protein loosing enteropathy
7	Plasma	Hypoproteinemia, liver diseases, coagulopathies, pancreatitis
8	Whole blood	Anaemia, hypovolemic shock, coagulopathies, chronic liver disease

 

Monitoring of fluid therapy

It can be observed by the close examination of the patient breathing, heart rate, temperature, blood parameters, bio-chemical parameters examination and renal output.

Common clinical condition and fluid of choice in veterinary practice

S No	Clinical condition	Fluid therapy
1.	Neonatal calf diarrhoea	Normal saline (0.9 %) + Sodium bi carbonate (1.3 %) + Dextrose (5 %)
2.	Lactic acidosis	Sodium bi carbonate (1.3 %)
3.	Acute diffused peritonitis	Balanced electrolytes
4.	Vagal indigestion	Balanced electrolytes
5.	Per acute mastitis	Balanced electrolytes
6.	Intestinal obstruction	Balanced electrolytes
7.	Milk fever	Calcium borogluconate
8.	Hypoglycemia	Dextrose 5 %, 10 %, 20 %, 25 %
9.	Fever	Normal saline
10.	Hypokalemia	Potassium chloride, Ringers lactate
11.	Hyperkalemia	Dextrose 5 %

 

Routes of administration of fluid

1. Oral route: Administration of fluid through mouth or oral cavity. It is the simplest mode of fluid therapy, advisable in salt toxicity and mild dehydration conditions. Safest route of fluid administration, large volume non sterile fluid can be given in short period of time. However not useful in patients with gastrointestinal pathology and in emergency conditions.

 

2. Subcutaneous route: Administration of fluid below the epidermis. It is indicated in mild vomition, diarrhoea, dehydration, cardiovascular collapse, chronic kidney disease and for the administration of maintenance dosage. Good for mild dehydration and maintenance dosage administration. However not advisable in severe dehydration due to possibility of small volume administration due to limited skin elasticity and it will be inadequate for acute or severe losses. Only isotonic non irritating solutions are administered by this route, hypo or hypertonic solution can’t be administered and there will be possibility of cellulitis will be more.
3. Intravenous route: Administration of fluids through veins. Indicated in shock, severe dehydration, vomition and diarrhoea. It is the ideal route for acute or marked fluid loss where large volume can be given rapidly in a short period of time, hypo and hypertonic solutions can be given in emergency condition. This route allows precise dosage, nutrients, blood and blood components can be given. Risk of over hydration, needs regular monitoring and it may cause phlebitis, sepsis, thrombosis due to improper administration.
4. Intraperitoneal route: Administration of fluids into peritoneal cavity. Precised route for large volume of fluid indications and mild to moderate dehydration conditions due to rapid absorption. Safest route in young animals. Chance of organ puncture or rapture and peritonitis are the complications by this route.
5. Intraosseous route: Administration of fluids directly into bone marrow. Main advantage is rapid access to vascular space and useful for very young, patients with severe vascular collapse. Sites in dog and cat includes inter-trochanteric fossa of proximal femur, medial aspect of proximal tibia distal to tibial tuberosity, proximal shaft of humerus, cranial aspect of mid diaphyseal of ulna. Osteomyelitis, fat emboli, damage to local nerves, damage to bone plates and deformity in young animals are the complications occasionally observed by the clinicians followed. Cannot administer large volumes due to small size and pain in intra medullary  cavity and osteomyelitis are the limitations.
6. Per Rectal route/Proctoclysis: Administration of fluids through rectum. In cattle & horse large intestine is the chief site of absorption of water. 5-20ml/kg BW fluid can easily be administered by this route. Safe in gastric irritation and vomition conditions. Safe route, rapid administration possible, cost effective and non-sterile fluid can easily administered in large volume, however due to rapid expulsion, not effective in emergency, proctitis and diarrhoea condition.

 

S No	Route	Animal	Site	Instrument
1	Oral	All animals	Oral	Stomach tube Nasogastric tube Pharyngostomy tube
2	Subcutaneous	All animals	Neck region Lateral part of abdomen	Needle and Infusion set
3	Intravenous	Cattle	Jugular vein, mammary vein and ear vein	IV Neeedle and infusion set
		Horse	Jugular vein	IV Neeedle and infusion set
		Dog, Cat	External cephalic vein Tarsal vein	Scalp vein set
4	Intraperitoneal	All animals	Ventral part of abdominal cavity	IV Neeedle and infusion set
5	Intraosseous	Dog, cat and laboratory animals	Inter-trocantric fossa of proximal femur 2.Medial aspect of proximal tibia distal to tibial tuberosity 3.Proximal shaft of humerus. 4.Cranial aspect of mid diaphysial of ulna	Intra-osseous needle
6	Perrectal	Cattle, Horse	Rectal	Rectal Syringe

 

Over hydration

Over hydration will be manifested by the clinical signs like increased serous nasal discharge, chemosis, peripheral oedema, pulmonary oedema and cerebral oedema.

Contradiction of fluid therapy

      Some of the condition where one should avoid the fluid therapy such as pulmonary oedema, brain injury, congestive heart failure and pulmonary contusion. Especially while giving fluid therapy one should continue checking for vital parameters. Before giving any fluid therapy, ask the owner with proper history and vital parameters one can proceed further fluid therapy decision.

Conclusion

Fluid therapy is one of the important steps in  clinical conditions to save the life of the animals. Fluid therapy works under normal to critical condition with proper dosage and administration.  Some times without accessing the clinical condition suddenly application of fluid therapy causes condition of patients to worst phase. Correct fluid at needed clinical condition saves a life of animals. So fluid therapy is life saving procedure in veterinary practice.

 

 

Reference:

·         Crystalloid and colloid compositions and their impact., 2021. Elke Rudloff and Kate Hopper. Frontiers in veterinary science. Volume 8, pp: 1-11

·         Emergency fluid therapy in adult cattle., 2020.  Melanie Spahn-Holmes. Improve veterinary practice.

·         Hand book of veterinary Medicine. ICAR publication

·         Intravenous and Oral Fluid Therapy in Neonatal Calves With Diarrhea or Sepsis and in Adult Cattle., 2021. Peter D. Constable, Florian M. Trefz, Ismail Sen, Joachim Berchtold, Mohammad Nouri, Geoffrey Smith and Walter Grünberg. Frontiers in veterinary science. Volume 7,  pp: 1-29

·         The Fluid Resuscitation Plan in Animals by MSD Veterinary Manual

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