Association of Clostridium difficile with enterocolitis and lactose intolerance in a foal

Diagnoses of Clostridium difficile enterocolitis and lactose intolerance we re made in a neonatal foal with persistent diarrhea. It was determined that the foal had lactose intolerance on the basis of the results of a lactose tolerance test, and a diagnosis of C difficile enterocolitis was subsequent ly made. The foal responded to oral administration of metronidazole and lac tase. Lactose intolerance is a secondary problem most commonly associated with ro tavirus infection, but it can be caused by any condition affecting the smal l intestine. Because C difficile can affect the small intestine in foals, i t was presumably the cause of the lactose intolerance in this foal with per sistent diarrhea. Oral administration of lactase was not initially successf ul in this foal, most likely because of ongoing C difficile enterocolitis. Presumably, metronidazole was an effective treatment for C difficile entero colitis and administration of lactase allowed for normal digestion of milk until endogenous lactose production returned. Clostridium difficile enteroc olitis and lactose intolerance should be considered as differential diagnos es in neonatal foals with diarrhea, especially when the foal is bright and alert.