A survey of the incidence of Neospora caninum infection in aborted and stillborn bovine fetuses in England and Wales.

Selected brains and fetal viscera from 190 aborted or stillborn bovine fetuses submitted to Veterinary Investigation Centres in England and Wales between August 1992 and January 1993 were examined histologically. Non-suppurative inflammation of the brain and/or myocardium and placental cotyledons was identified by light microscopy in 20 (10.5 per cent). An immunocytochemical examination of fixed tissue sections using antisera against Neospora caninum, Toxoplasma gondii and Sarcocystis species revealed positive immunolabelling for N caninum in the brains of eight (4.2 per cent), but no labelling with anti-T gondii or anti-Sarcocystis species antisera was evident. These results suggest that N caninum may be an important cause of reproductive failure in cattle in England and Wales.