Diagnóstico molecular e histopatológico de Neospora caninum en fetos bovinos abortados de ganaderías de la sierra ecuatoriana

Abstract

Neosporosis is one of the main causes of abortion in cattle worldwide, generating significant economic losses in meat and milk production, which is why its diagnosis is important. The objective of this study was to determine the presence of Neospora caninum in aborted bovine fetuses through histopathological and molecular diagnosis. Fifty-six fetal samples were collected from cattle farms in the Ecuadorian highlands, with fetal ages ranging from 4 to 9 months. The presence of parasite DNA in brain tissue was analyzed by PCR, detecting positive cases in 75 % of the fetuses analyzed (46/56). In the histopathological analysis, 73,2; 66,1; 62,5; 62,5; and 50 % of the fetuses presented lesions compatible with Neosporosis in the brain, liver, heart, lung, and tongue, respectively. A higher frequency of lesions and positive PCR results was observed between the fourth and seventh months of gestation. In addition, serological results were recorded with a positivity rate of 42,9 % in fetuses and 32,1 % in mothers. No association was found between the presence of lesions and fetal sex and age variables. The concordance between the presence of brain lesions and PCR was low. This study allows us to determine that a high number of the fetuses analyzed have molecular and histopathological evidence of N. caninum infection. As this is the first study reported in the country on aborted fetuses, it provides significant information on the circulation of this parasite in cases of abortion in dairy cattle in the Ecuadorian highlands.