Treating Diarrhea in Foals

Diarrhea in foals is not uncommon; can be related to a variety of causes; and is often self-limiting, clearing up without treatment. However, diarrhea is a sign that something is not right, and severe diarrhea can dangerously dehydrate a foal.

Infection can be a cause of diarrhea. Some cases, often those caused by rotavirus, occur because rotavirus damages the intestinal cells that secrete digestive enzymes and absorb nutrients. Fluid, sugars, and other nutrients aren’t being pulled out of ingested material and absorbed by the intestine. In other cases, an excess of fluid is secreted into the intestine. This type of diarrhea is more commonly related to a bacterial infection. Both situations result in loose, watery stools. Treatment includes supportive care such as fluid therapy if necessary. Identifying the cause of infection can be done by fecal analysis, and an appropriate antibiotic may be prescribed. Some foals respond well to treatment with oral bentonite, a clay that bonds toxins and coats the intestinal wall to prevent absorption of toxic material.

Other cases of diarrhea seem to be associated with changes in feed. Making any change gradually over a period of several days will help to minimize digestive upsets. Foals also commonly develop loose stools about a week to 10 days after birth when the dam comes into heat. This usually occurs when foals begin to nibble on the mare’s manure and microbial populations change in the foal’s intestine. Foal heat diarrhea generally resolves within a few days.

It’s a good idea to monitor foals that develop diarrhea. Owners should seek veterinary help if the condition is severe or lasts more than a couple of days, or if foals develop other signs of disease. Diarrhea can be a sign of sepsis (severe bacterial infection). Any foal that is lame or has swollen joints and spends excessive time lying down or sleeping should be examined by a veterinarian as soon as possible.