Clinical, pathological and diagnostic aspects of congenital neosporosis in a series of naturally infected calves.

摘要

In this study, several Belgian Blue beef and Holstein-Friesian dairy calves from a single farm in Belgium which showed clinical signs compatible with congenital neosporosis were examined [date not given], and the performances of the different diagnostic tools were also evaluated. The calves with clinical signs were euthanized after clinical examination for postmortem evaluation. Blood was also collected from newborn calves before receiving colostrum and from their dams. Histopathology, immunohistochemistry (IHC), polymerase chain reaction (PCR) and the indirect fluorescent antibody test (IFAT) were used to analyse the brain and serum samples. A total of 7 calves were examined, which had clinical signs of ataxia and recumbency. Postmortem examination did not reveal any macroscopic lesions but histopathological examination of the brain tissue by PCR in 4 calves revealed lesions compatible with Neospora caninum infection. IFAT analysis showed that all but one calf had high levels of N. caninum antibodies before they received colostrum. The dams were all seropositive. These results show that the combined use of histology, IHC and PCR enables the confirmation of N. caninum infection in calves with neurological signs..