Prevalência, alterações clínicas e histológicas cutâneas associadas à infecção por Trypanosoma caninum e Leishmania chagasi em cães domésticos

Abstract

Leishmania chagasi is one of the main trypanosomatids that cause dermatopathy in dogs, but Trypanosoma caninum has been isolated in dog skin in several regions of Brazil. The objective of this study was to investigate the prevalence of T. caninum in dogs in order to investigate possible clinical and histological skin changes associated with infections by this agent and to compare the findings to those obtained with L. chagasi infection. Of the 150 dogs surveyed, a T. caninum infection was detected in three (2%) dogs and an L. chagasi infection in 15. There was no statistically significant association (p> 0.05) with race, sex, age, and the presence of dermatopathies. Dermatological changes were observed in one (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. chagasi, respectively. In the histopathological analysis of the skin of dogs infected with T. caninum, two dogs did not show clinical dermatopathy. These dogs showed a perivascular infiltrate with a mild lymphoplasmacytic inflammatory infiltrate. The dog with clinical dermatological alterations showed a co-infection with fungi of the genus Microsporum sp. and Trichophyton sp., which was associated with acanthosis, epidermal orthokeratotic hyperkeratosis, and the presence of melanomacrophagous. The most common finding in the skin analysis of dogs infected with L. chagasi was chronic granulomatous inflammatory infiltrate. One dog was found to have a structure that was morphologically consistent with amastigotes of Leishmania sp. The presence of nonspecific changes found in the histology of dogs with and without dermatopathies leads us to infer that T. caninum may not induce a cutaneous inflammatory reaction; however, more studies are necessary to better characterize the clinical and histological changes induced by this agent.