OBJECTIVE:

To develop accurate, objective guidelines for assessing hydration status of neonatal calves with diarrhea.

DESIGN:

Prospective study.

ANIMALS:

15 male dairy calves 3 to 10 days old.

PROCEDURE:

Dehydration and diarrhea were induced by administration of diuretic agents (i.e., furosemide, spironolactone, hydrochlorothiazide) and sucrose solution. Linear regression was used to examine the relationship between potentially useful factors for evaluating hydration status (extent of enophthalmos; skin-tent duration on neck, thorax, and upper and lower eyelids; heart rate; mean central venous pressure; peripheral [extremity] and core [rectal] temperatures; core-peripheral [rectal-extremity] temperature difference; PCV; and hemoglobin and plasma protein concentrations) and degree of dehydration, as determined by change in body weight.

RESULTS:

Best predictors of degree of dehydration were extent of enophthalmos, skin elasticity on neck and thorax, and plasma protein concentration.

CLINICAL IMPLICATIONS:

These experimentally determined guidelines provide practitioners with a simple, inexpensive, and practical method for evaluating hydration status of neonatal calves with diarrhea.