This document discusses fluid therapy in animals. It begins by describing the distribution of water in the body and the composition of intracellular and extracellular fluids. It then discusses three types of fluid disturbances: changes in volume, content, and distribution. The document outlines different types of fluid therapy including replacement, adjunctive, and supportive therapies. It provides details on routes of fluid administration and indications for intravenous fluids. Throughout, it discusses evaluating and monitoring fluid therapy, diagnosing and treating dehydration, and complications of intravenous fluids.

1. Fluid therapy in animals
Dr Vinodh Kumar O.R
Senior Scientist
ICAR- Indian Veterinary Research Institute
Bareilly, Uttar Pradesh

2. Distribution of water in
body

3. Composition of IC & EC fluids

4. Three types of fluid disturbances:
 1. Changes in volume (e.g., dehydration, blood loss)
 2. Changes in content (e.g., hyperkalemia)
 3. Changes in distribution (e.g., pleural effusion)

5. Fluid therapy Types
 Replacement therapy:
Therapy in which we infuse same type of fluid
which is lost from body .
 Adjunctive Therapy:
One type of fluid is given to remove other type of
fluid e.g. mannitol 25% is given in case of ascites
and edema.
 Supportive Therapy:
Fluid is given to animal just to support him to cure
quickly i.e. amino acids, minerals, multivitamins
and carbohydrates etc.

6. Different routes of fluid
administration

7. Different routes of fluid
administration

8. Indications for intravenous fluids
 Replace extracellular fluid volume
losses
 Maintain fluid and electrolyte
balance
 Correct existing electrolyte or acid-
base disorders
 Provide a source of glucose

9. Reasons for Fluid Therapy
 Vasoconstriction
 Pale mucous membranes
 Prolonged capillary refill time
 Peripheral temperature < core temperature
 Reduced urine output
 Decreased mentation
 Tachycardia (cats may present with bradycardia)
 Hypotension (poor pulse quality)
 Reduced oxygen saturation (low SpO2)
 Lactate >2 mmol/L
 Metabolic acidosis/Alkalosis

10. Evaluation and Monitoring Parameters for
fluid therapy

11. Dehydration
 Dehydration or the loss of fluid from the interstitial
space in the form of increased fluid loss from
vomiting, diarrhea, or polyuria is one of the main
cause of water reduction in body.
 Signs include decreased skin tenting, sunken eyes,
depressed mentation, and tacky/dry mucous
membranes, CRT 2-3 sec in mild cases and >3 sec in
severe cases, Slight depression of eyes into sockets.

12. Determining a patient's degree
of dehydration
 5%-6% dehydrated: Subtle loss of skin elasticity
 6%-8% dehydrated: Definite delay in return of skin to
normal position (skin turgor), slight increase in capillary
refill time, and eyes may be slightly sunken into orbits
 10%-12% dehydrated: Extremely dry mucous
membranes, complete loss of skin turgor, eyes sunken
into orbits, dull eyes, possible signs of shock
(tachycardia, cool extremities, and rapid and weak
pulses), and possible alteration in consciousness
 12%-15% dehydrated: Definite signs of shock; death is
imminent if not corrected

13. Assessing for Fluid Therapy
 The first step in determining whether a
patient needs fluid therapy is a full
physical examination, including collection
of a complete history.
 Check perfusion of tissues
 Check for dehydration, and evaluate
losses from any of the fluid
compartments.
 Patients that cannot adequately perfuse
their tissues require immediate
intervention with fluid therapy to restore
perfusion and correct shock.

14. IV fluid therapy indicates that
the assessment of patients
should include
 Physical examination
 Observation of vital signs over
time
 Clinical presentation.

15. Diagnosing Dehydration
 Physical exam
 Weight loss
 PCV (HCT) increased
 Albumin or total protein
increased
 BUN, creatinine
 Prerenal azotemia

16. Clinical examination of Degree of
Dehydration

17. Shock

18. Five ‘Rs’ of intravenous
fluid administration
 Resuscitation
 Routine maintenance
 Replacement
 Redistribution
 Reassessment

19. Resuscitation
 To ascertain the fluid
requirements of patients who
are acutely ill, an accurate
assessment is needed and
should include the ABCDE.
 Routine maintenance fluids are
needed in patients who are at
ongoing risk of fluid loss.

20. Replacement
 Assessment should focus on:
 Ensuring adequate hydration;
 Ensuring electrolyte balance;
 Checking for any potential fluid overload.
 Alterations in potassium – either
hypokalaemia or hyperkalaemia – can
affect patients’ cardiac performance
causing arrhythmias, heart failure and/or
cardiac arrest.
 If continued fluid loss is suspected, this
should be checked and losses monitored.

21. Redistribution
 Redistribution of fluid can occur in
critical illness. Fluid is lost from the
circulatory volume and moves into
the tissues; this is called ‘third
space loss’.
 Monitoring of central venous
pressure, kidney function tests or
high dependency care, may be
required.

22. Reassessment
 Regular reassessment of patients’
fluid therapy needs is essential.
 Enteral routes reduce the need for
IV access and, in doing so, reduce
the risks of ongoing IV therapy, such
as catheter-related infections

23. Different types of IV fluids

24. Crystalloids
 Crystalloid solutions are isotonic plasma
volume expanders that contain
electrolytes.
 Isotonic fluids can increase the
circulatory volume without altering the
chemical balance in the vascular spaces.
 Crystalloid solutions are mainly used to
increase the intravascular volume when it
is reduced (haemorrhage, dehydration or
loss of fluid during surgery)

25. Colloids
 Colloids are gelatinous solutions that
maintain a high osmotic pressure in the
blood.
 Colloids are too large to pass semi-
permeable membranes such as capillary
membranes, so colloids stay in the
intravascular spaces longer than
crystalloids.
 Examples : albumin, dextran, hetastarch,
Haemaccel and Gelofusin

26. Which fluid to administer?
 Crystalloids and colloids are plasma
volume expanders used to increase a
depleted circulating volume.
 Both are suitable in fluid resuscitation,
hypovolaemia, trauma, sepsis and burns,
and in the pre-, post- and peri-operative
period.
 Colloids carry an increased risk of
anaphylaxis, are more expensive.

27. Comparison of crystalloid and
colloid solution

28. Rules of IV fluid therapy

29. Rules of IV fluid therapy

30. Clinical characteristic of IV fluids
 Ringer lactate is the most physiological iv fluid
 Isotonic saline and DNS have maximum sodium Isotonic saline
 DNS and ISO-G have maximum chloride
 Isolyte – E,P,M directly correct acidosis
 Isolyte -G only iv fluid which directly correct metabolic
alkalosis.
 Isolyte- M,P,G,E and Ringer lactate are usually avoided in
renal failure.
 Isolyte- G and Ringer lactate are avoided in patients with liver
failure.

31. Clinical characteristic of IV
fluids
 Isotonic saline and Ringer Lactate do not
contain
glucose so preferred fluid for diabetic
patients.
 D5,D10 and D20 are only fluids which do not
contain Na and Cl.
 Isolyte -M and P have low Na and Cl.
 NS , DNS and dextrose containing fluids do
not
contain potassium and they do not correct
metabolic acidosis and alkalosis directly.

32. Characteristics of intravenous
fluids

33. IV fluid advantages and
disadvantages ication

34. Crystalloid classification
Maintenance fluid Replacement
fluid
Special fluid
5% Dextrose Normal Saline 25% Dextose
Dextrose with
0.45%
Normal Saline
DNS Sodium bi
carbonate
Ringers lactate Potasium
Chloride
Isolyte- M, P, G

35. Complications of intravenous
fluids

36. Fluid therapy in small animals

37. Principles of Rehydration
 Correct dehydration, electrolyte, and
acid-base abnormalities prior to surgery.
 Do not attempt to replace chronic fluid
losses all at once.
 Severe dilution of plasma proteins, blood
cells and electrolytes may result
 Aim for 80% rehydration within 24 hours
 Monitor pulmonary, renal and cardiac
function closely

38. Example
An adult 18kg cat with 6% dehydration comes into the clinic. It
is estimated that the cat vomited 150 ml of fluid overnight
• Maintenance fluids can be dosed at 50 ml/kg/day in adults and
110 ml/kg/day in young animals
• Calculate maintenance volume
18kg x 50 ml/kg/day = 900ml per day
• Rehydration fluid is based on the estimated percent of
dehydration
% dehydration x weight in kg = deficit in liters

39. Example
Calculate replacement for dehydration 6% = 0.06
0.06 x 18 kg = 1.08 l
1.08 l x 1,000 ml/l = 1080 ml
1080ml x 0.8 (80% of dehydration value replaced
in 24 hours) =840 ml to replace on first day
• Take estimated volume lost in fluid and add to
the other volumes
• Final step: Take all values and add together
900ml + 840 ml + 150 ml = 1890ml

40. Indications of fluid overload
 Serous nasal discharge
 Increased respiratory rate (Dyspnea)
 Crackles or muffled lung sounds on
pulmonary auscultation
 Late stage consequence = pulmonary
edema (or pleural effusion in cats)
 Decreased PCV
 Increased BP

41. SC fluids injection site in
dogs

42. Cats SC fluid site

43. IV in cats

44. IV in dogs

45. Intraosseous catheter placed in
the femur