The short answer is not enough is known about this all-too-common veterinary emergency. There are no clearly defined criteria to categorize acute colitis. “Colitis in horses is very complex and can be affected by several factors,” says Ontario Veterinary College researcher, Dr. Luis Arroyo. There is a need to improve diagnostic protocol. Together with newly recruited faculty member Dr. Luiza Zakia, a global study is about to commence to develop a core outcome set (COS) for acute colitis in horses.
“By definition, equine colitis means inflammation of the colon,” says Arroyo. “Now in horses, because they also have a very large cecum, technically speaking, it should be called typhlocolitis, but for short, we only call it colitis.”
Arroyo goes on to explain although one of the hallmark clinical signs of colitis is diarrhea, not all horses with colitis will have diarrhea, and not all horses with diarrhea will have colitis. For example, a horse treated for impaction colic with ample oral fluids may develop transient diarrhea but not necessarily colitis. Causes of colitis can range from infectious origins, like a bacteria or virus but it could also be non-infectious, like a toxin or even stress related.