JOHNE'S DISEASE {MYCOBACTERIUM PARATUBERCULOSIS) IN A JIMELA TOPI (DAMALISCUS LUNATUS JIMELA)

A 10-yr-old male Jimela topi (Damaliscus lunatus jimela) born in captivity was eval uated by Veterinary Services, San Diego Zoo. The animal had a history of weight loss in the presence of a good appetite, abdominal distension, and intermittent soft feces. Clinical evaluation revealed a marginal anemia, hypoproteinemia, hypoalbuminemia, a lymphocyte-neutrophil reversal, and mesenteric lymphadenopathy. Radiographs, per rectal colonie biopsy, comparative intradermal tuberculin skin tests, and attempts to isolate Salmonella sp. and Campylobacter sp. were all negative. Fecal smears revealed abundant acid-fast bacilli. A diagnosis of Johne's disease was made and the animal was euthanized. Necropsy revealed an emaciated animal with a mildly thickened and hyperemic small intestine, cecum, and large intestine; lymphadenopathy of the colonie, intestinal, and mesenteric lymph nodes; and a mottled, soft friable liver. Histopathologic evaluation revealed chronic diffuse granulomatous inflammatory infiltrates in the small and large intestine, intra-abdominal lymph nodes, and hepatic peripheral lobular regions. There were abundant macrophages in all these tissues which contained large numbers of densely packed intracytoplasmic acid-fast bacilli. Mycobacterium paratuberculosis was isolated from the fecal cultures. Because of the potential transmission of Johne's disease to two adult female and three juvenile topi cohabiting with the infected animal, all herd mates were euthanized. Serologie, comparative skin tests, histopathologic evaluation, and fecal examination failed to indicate the presence of mycobacterial organisms or disease in any of these animals.