Histopathological findings and immunohistochemical staining of Neospora caninum infection in placentas of animals for slaughter

Bovine neosporosis is a parasitic disease caused by the protozoan Neospora caninum, which is one of the main pathogens that cause abortions in cattle worldwide. It is responsible for large losses in dairy and beef cattle, especially with regard to the expenses associated with decreased productivity and increased discard. In the State of Maranhão, the occurrence of this parasite has already been confirmed in the dairy cattle of three microregions that make up the state’s dairy industry and in small ruminants of the municipalities of Amarante do Maranhão and Buritirana. This fact justifies the importance of determining the presence of N. caninum in cattle slaughtered in the slaughterhouses of the Island of São Luís, to help control the parasitic cycle in the cattle production system of the region under study, and the importance of its diagnosis. The objective of the research was to conduct a histopathological and immunohistochemical characterization of bovine placentas infected with N. caninum collected in slaughterhouses. Sixteen placenta samples from cows were randomly selected at the slaughterhouses of the city of São Luís for histological analysis and immunohistochemistry. Results showed that 31% of the placentas presented histopathological changes such as: inflammatory process, edema, hemorrhage and presence of hemosiderin. All slides with histopathological changes showed immunolabeling for N. caninum.