How to Assess Calf Dehydration and Rehydration
By Dr, Jennifer Trout, Cargill Western U.S. Calf and Heifer Technical Pro
Dehydration in calves experiencing scours is often underestimated. A scouring calf can lose anywhere between 5 to 10% of its body weight in water within one day. Properly assessing dehydration and providing accurate rehydration can help calves rebound faster from scours and other ailments.
How to Assess Dehydration
*Calf may be too dehydrated for fluid correction via IV therapy.
Dehydration % – Percent of water loss relative to total body weight. Use this percent to calculate the amount of electrolyte solution for dehydrated calf.
Demeanor – Calf’s appearance and reaction to feeding and stimulation. Calves start to lose energy, become lethargic, and show signs of depression at 8% dehydration.
Sunken Eyes – This is also known as enophthalmos and is an early sign that calves are ill. To assess, pull down the lower eyelid and measure the gap at the inner corner of the eye from the eyelid.
Skin Elasticity – Pinch a fold of skin on the side of the neck and rotate it 90 degrees and observe the amount of time for the skinfold to disappear. If fold disappears in 2 – 5 seconds, the calf is between 8 and 10% dehydrated.
Oral Treatment – Provide electrolytes in the morning in addition to their meal. In hot weather, leave a bottle in between feedings and feed a bottle at night in addition to their meal.
IV Treatment – When a calf is 8 – 10% dehydrated, and has a poor or no suckling reflex, give fluids subcutaneous or with an IV. Consult with your veterinarian about treatment.
How to Calculate Rehydration
Don’t underestimate how much fluid calves need to rehydrate. Use the dehydration % determined from above and the calf’s weight to calculate the fluid amount needed.
1. Estimate the Dehydration
2. Use the equation (Weight x Dehydration %). To get the amount of solution in pounds for oral or IV therapy. To convert this number to quarts, divide by 2 (1 quart = 2 pounds).
3. Feed to rehydrate multiple times a day and continue feeding milk.
Example: 6% dehydration estimation on an 80-pound calf
That's 4.8 pounds (80 multiplied by .06) of lost fluid that needs to be replenished. A quart of electrolytes weighs two pounds. This calf needs about 2.5 quarts (4.8 divided by 2) of electrolytes to correct its dehydration alone.