Acute diarrhea in hospitalized horses

The development of diarrhea among hospitalized horses is a major concern for equine veterinary hospitals and referral centers. It is a potential complication of hospitalization for surgical or medical procedures and can contribute to the morbidity and mortality of horses with gastrointestinal and non-gastrointestinal diseases. Unfortunately, it can be difficult to pinpoint the exact cause of acute diarrhea or colitis, and in most cases, the specific etiologic agent is presumptive or undetermined. This article discusses the major etiologic agents of diarrhea in hospitalized horses, considers factors that place hospitalized horses at special risk for diarrhea, and examines several infectious colitis outbreaks that have occurred at veterinary referral centers.