Ulcerative enterocolitis in dogs induced by drugs.

An ulcerative enterocolitis was induced in dogs by two drugs; cinchophen given intravenously or indomethacin given orally. Ulcers were closely associated with Peyer's patches with either drug. Granulomata were occasionally seen in the mucosa and adjacent mesenteric nodes of dogs who received cinchophen. Transmural inflammation was seen only in some dogs who received indomethacin. A skip-like distribution of mucosal lesions was seen, induced by either drug and corresponding to the skip-like collections of lymphoid follicles. An explanation of the pathogenesis of these lesions is offered in the light of recent advances in the understanding of the immune response of gut-associated lymphoid tissue.