The role of Neospora caninum and Toxoplasma gondii in spontaneous bovine abortion in Argentina

The aim of the present work was to evaluate the role of Neospora caninum and Toxoplasma gondii infections in spontaneous bovine abortions in Argentina. Based on histopathological results, 70 presumptive cases of apicomplexan protozoal abortion from a total of 666 cases of spontaneous bovine abortion submitted to the National Institute of Agrarian Technology, Balcarce, from 1999 to 2007 were included in this study. N. caninum infection was diagnosed by an indirect fluorescent antibody test (IFAT), by immunohistochemistry (IHC) and by nested-PCR. T. gondii infection also was diagnosed by nested-PCR. DNA from fetuses was extracted primarily from CNS tissues. Heart, liver, muscle and/or placenta were processed when nervous tissue was not available. Sixty-six (9.9%) fetuses were positive by at least one technique (IFAT, IHC or nested-PCR) for N. caninum infection. Overall, there was poor agreement among results obtained by these diagnostic techniques. In contrast, no Toxoplasma-infection was detected in any aborted bovine fetus.