Question of the Day

This calf is approximately 10% dehydrated based on tacky (dry) mucous membranes (mm), tachycardia, sunken eyes, weak pulses, and extremely prolonged skin turgor. Diarrhea is a common issue in neonatal ruminants that can cause substantial economic losses.

It is helpful to estimate percent dehydration in order to assist in formulating a fluid resuscitation plan. An 85-kg calf that is 10% dehydrated requires at least 8.5 L of IV fluids to rehydrate (85 kg x 0.10 = 8.5 L).

Guidelines across species: 
5% (least amount detectable on physical exam): mildly tacky mm 
7%: tacky mm, mild tachycardia, mild loss of skin turgor 
10%: tacky mm, tachycardia, sunken eyes, weak pulses, and extremely prolonged skin turgor 
>10%: as for 10% + coma, +/- death

Here is a nice article describing calf dehydration parameters, courtesy of Cornell Coop Ext.