Hematological, biochemical and anatomopathological aspects of the experimental infection with Trypanosoma evansi in dogs

Abstract

O presente estudo acompanhou durante 82 dias o curso da infecção experimental com T. evansi em quatro cães, realizando a avaliação dos achados hematológicos, bioquímicos e anatomopatológicos. Os animais infectados mostraram declínio acentuado na contagem de hemácias, hematócrito e teor de hemoglobina, permanecendo anêmicos a partir da terceira semana de infecção até o final do período experimental. Leucopenia com neutropenia foram observadas entre a segunda e a quinta semanas após a infecção. Os cães inoculados desenvolveram hiperproteinemia, sendo constatada diminuição na relação albumina:globulina. As atividades séricas de alamina aminotransferase e aspartato aminotransferase aumentaram significativamente nos cães infectados em relação aos animais controle. O exame histopatológico revelou hiperplasia linfóide no baço e linfonodos e infiltrado mononuclear periportal e esteatose de padrão centrolobular no fígado de todos os cães infectados. Intenso infiltrado mononuclear foi observado no miocárdio de três cães e acúmulos de células mononucleares junto às meninges foram evidenciados em dois animais infectados.

The course of experimental T. evansi infection in four dogs was followed for 82 days and hematological, biochemical and anatomopathological findings were studied. Infected animals showed progressive decrease in red blood cell count and hemoglobin concentration, leading to anemia which persisted from the third week post-infection until the end of the study. Leucopenia and neutropenia were observed between weeks 2 and 5 of the infection. The infected dogs developed hyperproteinemia and a decrease in the albumin:globulin ratio was observed. Aspartate aminotransferase and alamine aminotransferase levels increased significantly in infected dogs in comparison to control dogs. Histological changes observed in all infected animals consisted of lymphoid hyperplasia in spleens and lymph nodes and centrilobular degeneration and periportal mononuclear cell accumulation in the liver. A massive mononuclear cell infiltration of the myocardium was seen in three dogs and a nonsuppurative meningoencephalitis was evidente in two infected animals.