Intestinal atresia was found in 29 animals and stenosis in five. Atresia was found in the duodenum in one pup; in the jejunum in nine calves, two lambs and one piglet; in the ileum in one pup, one lamb and one piglet; and in the colon in one foal, seven calves, one lamb, one piglet and three kittens. Stenosis was found in the duodenum of a foal, in the jejunum in two calves and one pup, and in both the ileum and the colon of a kitten. One lamb showed ileal atresia as well as ileal stenosis. We classified the atresia as type 1, membrane atresia (four cases); type 2, cord atresia (six cases); and type 3, blind-end atresia (19 cases). In the literature and our own study, atresia was found only in the small intestine in puppies, but in foals and kittens it was found only in the colon. Atresia of the colon is more common in animals than in man, but multiple atresia, frequent in man, is rare in animals.