Paratuberculosis in sheep: an emerging disease in Southern Iran

Based on gross and histopathologic lesions, paratuberculosis was diagnosed in sheep in Shiraz slaughter house, North of Iran. Ileocccal junction. ileum, jejunum, cecum, colon and associated mesenteric lymph nodes (MLNs) of 5000 carcasses were grossly inspected for wall thickness and/or corruption of the intestine and enlargement of the associated lymph nodes. Of these, 171 animals showed intestinal thickening and/or corrugation and MLNs enlargement and were suspected to paratuberculosis. However, at histopathological level only six animals exhibited moderate to severe lepromatous or tuberculoid granulomatous enteritis in cecum. colon, jejunum and particularly in the terminal ileum, ileocecal junction and the related lymph nodes. High numbers of acid fast organisms were present in terminal ileum and related MLNs and to it lesser extent in cecum, colon and jejunum. The rectal content of five of them were watery and soft and one of them had normal intestinal contents. The wall of ileum and to it lesser extent cecum, jejunum and colon were thicker and corrugated and the MLNs of ilcocecal valve, ileum. jejunum and cecum were larger than normal. The fat deposit surrounding the intestinal wall wits either absent or had a jelly shape or liquid appearance. Five sheep showed diffused or lepromatous type granulomatous reactions in their intestine and MLNs with diffused infiltration of lymphocytes, plasma cells, macrophages and rarely giant cells in the lamina propria and submucosa of the intestines and MLNs. The last one had follicular lymphoid infiltrates, with multifocal granulomas in the areas adjacent to payer patches in the ileum and to a lesser extent jejunum and cecum. The ileocecal, jejunal and cecal MLNs of this annual had Few Focal granulomatous reaction containing acid fast bacilli in the interfollicular areas of cortex and paracortical areas.