During recent years protozoa of the Neospora genus have been identified as a major cause of bovine abortions world wide (Barr et al. 1991, Mcintosh & Haines 1994, Thornton et al. 1991, Yaeger et al. 1994). A presumptive diagnosis of Neospora abortion can be made on the foetal histopathology as infected foetuses have a distinctive pattern of multifocal necrotizing and non-suppurative encephalitis often with an accompanying nonsuppurative myocarditis and a varying degree of focal inflammation in other organs (Barr et al. 1990, Thornton et al. 1991). However, confirming the diagnosis of Neospora abortion requires detection of protozoa in foetal tissues that react positively by immunohistochemistry with Neospora specific antisera (Barr et al. 1990, 1991).