Bovine cerebral theileriosis: a report on five cases with splenic infarction.

Five cases of bovine cerebral theileriosis are described. Macroscopically visible thrombosis of branches of the splenic vessels with associated infarction of the spleen are reported for the first time in this disease. The presence of Koch's bodies in thrombosed splenic vessels or vessels clogged with lymphocytes in the spleen is also a new finding. These changes were encountered in all five cases.