Infecção por Hepatozoon sp. em cães da área urbana do município de Uberlândia, Minas Gerais, Brasil

Abstract

Hepatozoonosis is a disease that affects dogs and it is transmitted by the ingestion of infected ticks with the oocyst of the Hepatozoon sp.. This study was held in order to determine the occurrence of this parasite in the urban área of the city of Uberlândia, Minas Gerais, Brazil, using the blood smear, to compare the best collecting methodology for the diagnosis, to determine the level of parasitaemia in the smears and also to associate the infection to behavioral and clinical features. Peripheral and circulating blood were collected from each animal and they were used to make blood smears using the May Grunwald-Giemsa method for gametocyte research of Hepatozoon sp.. Epidemiological questionnaires were applied to those responsible for the animals in order to obtain data about age, sex, breed, as well as behavioral and clinical aspects. An inspection exam was held to verify the presence of ticks and they were collected and identified according to their species. Hemolymph smears from the ticks were prepared using the May Grunwald-Giemsa method and analysed for the possible presence of oocysts. From all the animals that participated in the study, 120 were from the Hospital School of the Faculty of Veterinary Medicine of the Federal University of Uberlândia, 80 from private clinics and 100 from the Animal Protection Association (APA). The Hepatozoon sp. Occurrence was of 7,66% and there was not a significant statistic difference between the diagnosis made by smears collected from peripheral and circulating blood. The level of parasitaemia on the smears varied from 0,5 to 10%. Among the animals that were from the Veterinary Hospital and private clinics, the largest infection occurrence was between the ages of 0 and 1, however, at APA, 21,43% of the infected animals were adults. Of all the animals, 10% of the female ones and 4,16 % of the male ones were positives (p > 0,05) and 12,57% from an undefined breed and 2,12 % purebred were infected (p < 0,05). The main symptoms presented by the animals were the increase of heart frequency, pale mucosae, enlarged lymphnodes and spleen, ocular secretion, renal sensitivity, diarrhea, constipation, anorexia and weight loss. All collected ticks were from the species Rhipicephalus sanguinus and it was not found any evolutionary form of the parasite in the hemolymph of the ixodids. The findings of this study reinforce the presence of the Hepatozoon sp. infecting dogs from Uberlândia, Minas Gerais, while age and race may be related to the infection. The symptoms presented by the animals were compatible to those found by other researchers.