Fluid therapy in cattle

Question 1

Hypertonic saline exerts its beneficial effect by

Answer 1

rapid plasma volume expansion.

Question 2

Hypertonic saline IV dosage adult cattle

Answer 2

7.2% NaCl 4-5 ml/kg (2400 mOsmol/L) IV over 4-5 minutes and should immediately be provided with access to min 20- 40L drinking water.
If they don’t drink, then pump 20L into the rumen.

e.g. 600 kg cow gets 3L HS i.v.

Question 3

Hypertonic saline IV dosage calves

Answer 3

4-5 ml/kg ml 7.2% NaCl

e.g. 50 kg calf gets 250 ml IV

and 2-3 L isotonic alkalinizing oral electrolyte solution offered PO

Question 4

Main contraindication for hypertonic saline admin.?

Answer 4

hypernatremia (hyperosmolality),
especially renal failure cases

Question 5

Indications for IV hypertonic saline therpay in ruminants. (3)

Answer 5

> 8% dehydration
endotoxemia
hemorrhagic shock

Question 6

How would you mix a homemade hypertonic saline solution?

Answer 6

Products are available commercially.

Or formulate by adding 72 g of NaCl to 1L distilled water.

Question 7

What do you need to assess before starting fluid therapy?

Answer 7

• Does the presumptive diagnosis include an acidosis or alkalosis?
• How severe dehydration %?
• Fluid composition? Isotonic or some hypertonic solution

Question 8

What IV solution would you choose for a metabolic acidosis and what would you choose for dehydration therapy?

Answer 8

5,4% NaHCO3 (baking soda) for metabolic acidosis

+ Need to calculate base requirements in case of metabolic acidosis.

7,2% NaCl for dehydration therapy

Question 9

IVFT neonates vs adults

Answer 9

Mature cattle twice as likely to be
alkalotic than calves.

Question 10

How to calculate base requirements in case of metabolic acidosis.

Answer 10

Acidosis corrected with conversion factor of extracellular volume: 0.3.

Base deficit * 0,3 * BW(kg)

Bicarbonate conversion:
* 8.4% = 1 mEq/ml
* 5% = 0.6 mEq/ml
* 1.3% (isotonic) = 0.15 mEq/ml

Question 11

Maintenance fluids formula for adult cows:

Answer 11

100 ml/kg BW or

3,5-5% of BW

Question 12

dehydration % “cut off” for giving oral fluids alone:

Answer 12

8% dehydration

Not a hard rule and based on clinical
evaluation.

Question 13

IV Administration Rate Limit

Answer 13

40ml/Kg/hour to adult cattle with normal cardiovascular function.

One 14 gauge catheter only allows 20ml/kg/hour in a 500Kg cow.

Therefore, in most situations intravenous fluids can be safely administered to mature cattle through a 14-gauge catheter as
quickly as they will flow by gravity.

Question 14

Assessment of dehydration level by

Answer 14

skin tenting and eye recession.

Question 15

Clinical symptoms that help evaluate dehydration in calves.

Answer 15

diarrhea
depression, weakness
skin tenting prolonged
sunken eyes
prostration
tacky or dry mucous membranes
cool extremities

Question 16

Most common reason for metabolic acidosis in calves?

Answer 16

loss of bicarbonates with diarrhea

Question 17

Fluid therapy options in case of metabolic
acidosis.

Answer 17

Alkalizing solutions: bicarbonates, lactate, acetate, gluconate and citrate – bind hydrogen ions.

Available in the Estonian market: Ringer-lactate, 4,2% and 8,4% bicarbonate solutions, Ringer acetate.

Isotonic bicarbonates most suitable for diarrheic calves.
 250 ml 8.4% bicarbonate solutions mixed with 5 l of isotonic solution.
 8.4% bicarbonate solutions should not be administered alone!

 Acetate and lactate metabolize into bicarbonates.
 Ringer-lactate consists of L- and D-lactate!
 Dextrose solutions for newborn calves in case of hypothermia.

Question 18

Calculation of base deficit (BD)

Answer 18

Requirement for total alkalizing agent (mEq) = base deficit (mEq/l) x 0,3 x BW.

 For calves use conversion factor 0,6 because most of the BW is extracellular
fluid.

 If not possible to measure, use base deficit default 10 mEq/l.

Rule of thumb:
 Recumbent calf - dehydration 12-15%, BD 15-20 mEq/l.

 Weak calf – dehydration 8-12%, BD 15 mEq/l.

 Ambulatory calf - dehydration 5-8%, BD 5- 10 mEq/l.

Question 19

Base deficit rules of thumb for calves in varying states of dehydration.

Answer 19

Rule of thumb:
 Recumbent calf - dehydration 12-15%, BD 15-20 mEq/l.

 Weak calf – dehydration 8-12%, BD 15 mEq/l.

 Ambulatory calf - dehydration 5-8%, BD 5- 10 mEq/l.

Requirement for total alkalizing agent (mEq) = base deficit (mEq/l) x 0,6 x BW.

For calves use conversion factor 0,6 because most of the BW is extracellular
fluid.

Question 20

Example calculation for base deficit calf.

50 kg calf
use base deficit default 10 mEq/l

Requirement for total alkalizing agent (mEq) = base deficit (mEq/l) x 0,6 x BW.

Answer 20

10 x 0,6 x 50 = 300 mEq

1 g = 12 mEq of bicarbonates

 1 litre of 4,2% Na-bicarbonate solution contains 42 g of bicarbonates = 504 mEq
We need around 0,6 litres of this fluid.

 1,3% bicarbonate solutions = 13 g in 1 litre or 156 mEq/l so in that case, 2 litres of isotonic Na-bicarbonate solution is needed.

Question 21

State of potassium in acidosis?

Answer 21

It has been generally accepted that acidosis results in hyperkalemia because of shifts of potassium from the intracellular to the extracellular compartment.

Question 22

What molecule is important in potassium transport into cells?

Answer 22

glucose

So in hypoglycemic calves with diarrhea and thus dehydration induced hyperkalemia - administer glucose as well, to get that K back into the cells.

Question 23

calf oral electrolytes or IV?

Answer 23

Question 24

What conditions cause alkalosis in cows?

Answer 24

Almost every condition associated with loss of appetite and gastrointestinal stasis.

 Vagal nerve problems
 Torsion of the intestine, intussusception
 Displacement and/or torsion of the cecum
 Abomasal displacement and torsion
 Traumatic reticulitis
 Abomasal ulcers
 Peritonitis
 Renal failures
 Rumen indigestion and putrefaction, atony

Question 25

Fluid therapy in case of metabolic alkalosis.

Answer 25

Hypocloremia, hypokalemia, dehydration are present.

Thus, administer fluids rich in chlorides and potassium.

 Fluids should contain 135-155 mEq/l Na, 150-170 mEq/l Cl and 10-20 mEq/l K.

Use isotonic solutions - 0,9% NaCl or Ringer solution into which you can add KCl 20-40mEq/l but safer to administer orally.

Administering enough fluids and electrolytes kidneys can correct the alkalosis.

Question 26

Response to fluid therapy in cattle.
Expected positive reactions?
Undesirable reactions?

Answer 26

Expected positive reactions:
 Urination within 30-60 minutes, improvement of mental behavior, improvement of general condition.

Undesirable reactions:
 Dyspnoe – underlying pneumonia or too fast administration of fluids (pulmonary oedema).

 No urination –kidney failure, paralysis or muscular spasms of bladder.

 Sudden muscular weakness – due to hypokalemia.

 Dyspnea and tachycardia – over-administration of fluids.

Question 27

ORS

Answer 27

oral rehydration solution

Question 28

Fluid therapy with ORS.

Answer 28

 Essential to evaluate the function of rumen before administration.

 Exclude rumen acidosis!

 Always when calf has a suckle reflex and her condition is stable .

 Keep time gap of 2-4 hours between feeding milk and ORS.

 ORS with acetate or propionate are more suitable when calves are fed milk.