Often this event coincides with the mares first postpartum heat, called the foal heat, but foal heat diarrhea also occurs in orphans on milk substitutes so seems unlikely to be related to the mares hormonal status. The key to recognizing foal heat diarrhea is that the foal is remains bright, alert, afebrile, and continues to nurse. The diarrhea usually lasts 3 days to a week. The foal should be monitored carefully for signs of infection and if they occur rapidly addressed, see below.

Though not the mares foal heat, the exact cause of foal heat diarrhea remains a bit of a mystery but it is believed it represents colonization of the large bowel by bacteria, a normal event in the foals life. Pathogens are not left off the hook either and include Rotavirus, Rhodococcus equi, Clostridial organisms, intestinal parasites. Even some physiological changes have all been implicated.

The biggest problem encountered is the scalding the feces can cause on the foal's perineum and legs. This is best addressed with careful washing, a thorough rinsing and application of a thick protectant like Desitin® or Vaseline®. Treating the diarrhea directly is usually not indicated and safety studies not done. Some recommendations have been Pepto-Bismol (adult human dose) or Immodium may be helpful...more.