Prevention and Outbreak Management of Foal Diarrhea

Diarrhea is among the most common clinical complaints in foals. According to the National Animal Health Monitoring System Equine ’98 study, diarrhea affected > 20% of foals within the first 6 months of age. Although diarrhea is common with enteritis(inflammation of the small intestine), diarrhea is not always associated with inflammation of the bowel. Before the veterinarian can consider a treatment course for diarrhea they must understand the mechanisms of diarrhea. Is it malabsorptive or seceterory diarrhea? Malabsorptive is the inability of the intestinal tract to reabsorb water and nutrients. Secretory diarrhea results in the hypersecretion of both water and electrolytes into the intestinal tract. In a general categorization, bacterial toxins (Ex. Salmonella or Clostridium spp.) may cause a secretory diarrhea while viruses (Ex. Rotavirus and Coronavirus) can result in a malabsorptive diarrhea. In severe infections both bacteria and viruses can result in both a secretory and malaborptive diarrhea Most infectious causes of diarrhea and enteritis result in signs of mild to severe abdominal pain. Diagnosing the cause of enteritis in foals can be difficult because of the myriad of potential causes. Obtaining historical information can provide clues to the etiology of the enteritis. Questions may include: Have there been or currently any other animals on the farm having fevers or diarrhea? Has the foal received any medications that may have predisposed it to diarrhea? Have there been any changes in management (Feeding, turnout and etc.)? What is the consistency of the feces? Fetid in odor? What is the age of the foal?