What causes diarrhea in adult horses?
In many cases of adult equine diarrhea, the horse recovers before the cause is known. The horse’s intestines, especially the large intestines and caecum, contain large numbers of ‘normal’ bacteria, of many different types, which are an essential part of the normal digestive processes. If the normal ‘balance’ of these bacteria is upset by a sudden change in diet or antibiotic treatment, digestion is upset and diarrhea may follow. When the normal bacterial population reorganises and returns to normal, digestion and faecal consistency also return to normal. Treatment with probiotics (see later) may help a speedy return to normality and, if used early, before diarrhea develops, may sometimes help prevent diarrhea. There are specific conditions that do require diagnosis and specific treatment. Infections, such as salmonellosis (infection with Salmonella spp. bacteria) can cause symptoms ranging from acute, severe diarrhea to chronic, more insidious diarrhea and weight loss. Some symptomless
