When testing antibiotics in rabbits Dalacin was shown to be the most effective in inducing enterotoxaemia in rabbits. Autopsy disclosed signs of enterotoxaemia even in some animals without previous symptoms. Histopathological lesions were found even in intestines macroscopically normal. Experiments proved that after application of tested antibiotics spread through intestinal mucosa and produced a loss of microbial balance. Rabbit is to be considered suitable for modelling antibiotic-induced enterotoxaemia.