Leprosy in wild armadillos (Dasypus novemcinctus) on the Texas Gulf Coast: anatomic pathology.

Recent studies of the "naturally occurring leprosy-like disease of wild armadillos" establish that the causative bacillus is genetically identical to M. leprae from human sources, and thus the disease is a zoonosis, sylvatic leprosy. A recent survey of 451 wild armadillos from the Texas Gulf Coast demonstrated sylvatic leprosy in 4.66%. This companion study reports the anatomic pathologic changes seen in the 17 leprous and 17 nonleprous armadillos necropsied in that survey. Findings support previous studies on the histopathology and pathogenesis of sylvatic leprosy, but a broader spectrum of histologic changes are noted.

Pathology of spontaneous and experimental infection of North American wild ruminants with Mycobacterium paratuberculosis.

Spontaneous paratuberculosis was studied in free-ranging and captive bighorn sheep (Ovis canadensis), and Rocky Mountain goats (Oreamnos americanus). Lesions of paratuberculosis in these species resembled the disease in domestic sheep and goats. Mycobacterium paratuberculosis cultured from bighorn sheep was used to orally infect bighorn x mouflon (Ovis musimon) hybrid sheep, elk (Cervus elaphus nelsoni), mule deer (Odocoileus hemionus), and white-tailed deer (Odocoileus virginianus). Clinical paratuberculosis developed only in mule deer and was characterized by poor growth and diarrhea. Gross lesions were mild in all species. Enlargement of mesenteric lymph nodes was mild to moderate; the wall of the distal small intestine was affected minimally. Focal to diffuse infiltrates of epithelioid macrophages and giant cells occurred in the cortex of mesenteric lymph nodes, around mesenteric lymphatics, and in the intestinal mucosa. Extraintestinal lymph nodes, spleen, liver, and lung were involved in some animals; focal necrosis and mineralization was present in all species but was severe and widespread in the cervids.