Submitted to: Veterinary Record
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 6, 1995
Publication Date: N/A
Interpretive Summary: Infection by the protozoan parasite, Neospora caninum causes abortion and neonatal deaths in cattle, sheep, goats, horses and dogs. Its life cycle and sources of infection are unknown. Transmission from the dam to the fetus in the only recognized mode of transmission. This parasite is a major cause of abortion in cattle in the U.S., Australia and New Zealand. Scientists at the Beltsville Agricultural Research Center and the Ministry of Agriculture, England, report for the first time abortion due to N. caninum in cattle from England. This report will be useful to veterinarians in practice as well as those in diagnostics.
Histological examinations were performed on selected brains and fetal viscera from 190 aborted or stillborn bovine fetuses submitted to Veterinary Investigation Centers in England and Wales between August 1992 and January 1993. Non-suppurative inflammation of the brain and/or myocardium and placental cotyledon was identified by light microscopy in twenty (10.5%). Subsequent immunocytochemical examination of fixed tissue sections using antisera against Neospora caninum, Toxoplasma gondii and Sarcocystis species showed positive immunolabelling for N. caninum in the brains of eight (4.2%). No labelling with anti-T. gondii or anti-Sarcocystis species antisera was evident in these cases. These results confirm that a significant number of aborted and stillborn bovine fetuses were infected by N. caninum and suggest that this organism may be an important cause of reproductive failure in cattle in England and Wales.