SEROLOGICAL EVIDENCE IMPLICATING NEOSPORA SPECIES AS A CAUSE OF ABORTION IN BRITISH CATTLE

By means of an immunofluorescence antibody test (IFAT), using in vitro cultured parasites as antigen, antibodies to Neospora species at titr es greater than or equal to 1/1280 were found in 11 of 120 Scottish ca ttle that had recently aborted but in only one of 97 cattle from herds in which there had been no recent abortions (P<0.01). The specificity of the antibodies was confirmed by the lack of cross reactivity betwe en samples with high titres to Neospora and toxoplasma antigen in a di rect agglutination test, and by the absence of reactivity at greater t han or equal to 1/640 in the IFAT of convalescent sera from cattle inf ected experimentally with Toxoplasma gondii, Sarcocystis cruzi, Eimeri a bovis, E alabamensis, Cryptosporidiurn parvum and Babesia divergens. These results demonstrate that Neospora species infection occurs comm only in aborting cattle in Britain, and that the IFAT may be a useful tool for investigating the infection.