USE OF METRONIDAZOLE IN EQUINE ACUTE IDIOPATHIC TOXEMIC COLITIS

Sixteen cases of acute idiopathic toxaemic colitis developed in a vete rinary hospital over a period of three years. Before the onset of coli tis, 15 horses had received antibiotics, 11 had undergone general anae sthesia and various surgical procedures, and 10 had been treated with non-steroidal antiinflammatory drugs. The horses had acute onset, prof use watery diarrhoea, profound depression, mild to moderate abdominal pain, reduced intestinal borborygmi, tachycardia, dehydration and endo toxic shock, Leucopenia, neutropenia and pyrexia were common early ind icators of impending colitis. Metronidazole appeared to be an effectiv e treatment; eight horses treated with metronidazole survived whereas five of seven horses that received other treatments, but no metronidaz ole, died or had to be euthanased, The aetiology of the colitis could not be determined, but the clinicopathological features resembled thos e of colitis attributed to an intestinal overgrowth of Clostridium per fringens type A. No Salmonella species were isolated from 52 samples o f faeces, colonic contents and colonic mucosa which were collected fro m the horses antemortem and postmortem.