Carcinoma of the small intestine of sheep in Iceland. A pathological and epizootiological study.

This paper deals with an unusually high incidence, i.e. 0.97 % of carcinoma of the small intestine found in Icelandic sheep. The tumours were situated in the jejunum and upper ileum. The macroscopic and microscopic pathology is described and compared with carcinoma of the small intestine of domestic animals and humans. Aetiological factors are discussed and the possibility of exposure to carcinogenic substances, especially nitrosamines in food concentrates, is suggested. Finally these findings are discussed in relation to current ideas on carcinogenesis in the intestines.