Paratuberculosis in saiga antelope (Saiga tatarica) and experimental transmission to domestic sheep.

Mycobacterium paratuberculosis was isolated in low numbers from the small intestine and associated mesenteric lymph nodes of a saiga antelope (Saiga tatarica) using routine culture techniques in spite of histologic evidence of high numbers of acid-fast bacteria in these tissues. Two newborn domestic sheep were fed the ground intestinal tissue containing acid-fast bacteria and the progression of the experimental disease was followed by fecal culture, immunodiffusion (AGID) and lymphocyte stimulation (LST) tests. One experimentally infected sheep developed progressive clinical illness 1 yr postinoculation. Few M. paratuberculosis were isolated from feces or tissues although an extensive granulomatous mycobacterial enteritis, lymphadenitis and lymphangitis were observed containing large numbers of typical acid-fast organisms. No clinical illness was observed in the second inoculated sheep after 18 mo of observation, although infection was demonstrated at necropsy. Both sheep developed AGID and LST reactions indicative of paratuberculosis. This study demonstrated that a difficult to culture isolate of M. paratuberculosis was responsible for paratuberculosis in captive wild ruminants and was transmissible to domestic sheep. Diagnosis of paratuberculosis in four of eight of the imported saiga antelope and in eleven of their 18 offspring indicates the importance of this disease in management of captive wild ruminants and the ease with which this organism can be transmitted.

An epizootic of besnoitiosis in captive caribou (Rangifer tarandus caribou), reindeer (Rangifer tarandus tarandus) and mule deer (Odocoileus hemionus hemionus).

Besnoitia sp. was diagnosed in two caribou (Rangifer tarandus caribou) which died of pneumonia at the Assiniboine Park Zoo (Winnipeg, Manitoba, Canada) in 1983. During the following 3 yr besnoitiosis spread to an isolated herd of caribou, to mule deer (Odocoileus hemionus hemionus) and to reindeer (Rangifer tarandus tarandus). Reduction of exposure to biting insects appears to have reduced the transmission of besnoitiosis within the reindeer herd. The morbidity rate was approximately 82% in caribou and 67% in mule deer over the age of 2 mo. Most animals with clinical signs were euthanized; this precluded an estimation of the disease-related mortality rate. Twenty-eight caribou, 10 mule deer and three reindeer have been euthanized or died as a result of this epidemic. Attempts to artificially transmit the disease to potentially susceptible intermediate and definitive hosts were unsuccessful.