THE MORPHOLOGY AND PATHOLOGY OF BESNOITIA SP IN REINDEER (RANGIFER TARANDUS TARANDUS)

Four of five reindeer (Rangifer tarandus tarandus) obtained from a Bes noitia sp. infected herd at the Assiniboine Park Zoo in Winnipeg, Mani toba, Canada, in October 1989, had evidence of mild dermatitis over th e articular surfaces of carpal and tarsal joints. Cysts of Besnoitia s p., either surrounded by inflammatory reactions or without evident hos t response, were present within the dermis, submucosa of the nasal tur binates, periosteum, tendons, testes and hooves. The light microscopic and histochemical features of Besnoitia sp. from reindeer were indist inguishable from those of other Besnoitia spp. described in cattle, ro dents and horses. The Besnoitia sp. cysts and organisms from reindeer were unique in that bradyzoite membrane micropores and cytoplasmic eni gmatic bodies were not observed. Two cats were fed cysts of Besnoitia sp. but no oocysts were detected in feces for 90 days post-infection.