Differential diagnosis of diarrhoea in horses over six months of age

Pertinent questions regarding the history of a horse with diarrhoea are listed, as are diagnostic procedures that might be included in a complete clinical work-up. For purposes of discussion, diarrhoea is regarded as "acute" or "chronic" wherein the former concerns cases where the features of the disease are severe with progressive electrolyte imbalance, dehydration, toxaemia, or other life-threatening manifestations and the latter refers to cases that have been prolonged for a month or more. Patterns of disease, including results of diagnostic techniques, are stressed. In the "acute" category, salmonellosis, haemorrhagic and oedematous colon (Colitis X), acute peritonitis, and Corynebacterium equi infection are discussed in some detail. In the "chronic" group, strongyle larval migrans, granulomatous enteritis, chronic liver disease, Corynebacterium equi infection and chronic salmonellosis are emphasized.