[Studies of diarrhea in young calves. 3. Effect of cyclophosphamide on histomorphology and microbial flora of the gastrointestinal tract in the calf].

One single intravenous injection of 60 mg/kg of cyclophosphamide caused the development of moderate to medium catarrhal enteritis in calves, within two to four days from injection. --Distally aggravating damage to epithelial cells in the small intestine, accompanied by shortening of villi, as well as usually complete lymphocyte depletion of the lymph follicles of Peyer's patches were the most conspicuous pathohistological findings obtained from the intestinal tract. Regular epithelial damage, including ulcerations and necroses, were recordable also from the colonic mucous membrane. --No remarkable change in the gastro-intestinal flora was recordable from calves killed two days from cyclophosphamide application, but the quantitative composition of the gastro-intestinal germ flora was found to be remarkably altered in those animals which had been killed four days after administration of the cytostatic. --Elevated coli counts in the rumen as well as in the proximal and distal parts of the jejunum and ileum and reduced anaerobic overall germ counts and bacteroides values in the cecum and rectum were the most conspicuous bacteriological findings. --The direct damaging action of cyclophosphamide on the mucous membrane as well as altered immunological reactivity of the experimental animals should be considered the triggering factors which actually caused considerable displacement in the quantitative composition of the gastro-intestinal flora in those calves which had been killed four days after cyclophosphamide application.