Neosporosis in Cattle

Neosporosis is caused by the protozoan parasite, Neospora caninum. It is essentially responsible for abortion in cattle and various neuro-muscular conditions in dogs. Until 1988, N. caninum was confused with Toxoplasma gondii, a closely related parasite (Dubey et al. 1988a,b). In 1989, Thilsted and Dubey reported the presence of cerebral and cardiac lesions in several aborted bovine foetuses originating from a single farm. In the following years the parasite was identified in the tissues of many bovine aborted fetuses but also of stillbon calves and, rarely, of clinically affected newborn calves (Dubey et al. 1989; Dubey et al. 1990; Anderson et al. 1991; Barr et al. 1991). Since then, N. caninum has been identified on all continents and is considered as a major cause of abortion in cattle (Dubey, 2005).