O gênero Hepatozoon compreende centenas de espécies que infectam aves, répteis, anfíbios e mamíferos, em todos os continentes de clima tropical e subtropical. No cão doméstico duas espécies são descritas, H. canis e H. americanum; a primeira presente na Europa, Ásia, África, América do Sul e nos Estados Unidos da América do Norte (EUA), e a segunda, diagnosticada até o momento somente nos EUA. No Brasil, a espécie que infecta o cão foi caracterizada como H. canis. Esta revisão objetiva detalhar alguns aspectos da hepatozoose canina, causada pelo H. canis e principais pontos de biologia, transmissão, patogenia e sintomas, epidemiologia e métodos de diagnóstico, enfatizando as pesquisas desenvolvidas no Brasil.

The genus Hepatozoon includes hundreds of species that infect birds, reptiles, amphibians and mammals, in all continents with tropical and subtropical climates. Two species have been described in domestic dogs: H. canis, reported in Europe, Asia, Africa, South America and the United States; and H. americanum, which so far has only been diagnosed in the United States. In Brazil, the only species found infecting dogs is H. canis. The objective of this review was to detail some aspects of canine hepatozoonosis, caused by H. canis, and the main points of its biology, transmission, pathogenicity, symptoms, epidemiology and diagnostic methods, with emphasis on research developed in Brazil.

A presença de infecção por Babesia spp. em cães de áreas rurais do Estado de São Paulo, Brasil foi investigada. Para tanto, 150 cães foram examinados por técnicas parasitológicas de esfregaços sanguíneos e moleculares (PCR), e também, foi verificada a presença de carrapatos nestes animais. Pela análise de esfregaços sanguíneos, 3 (2%) dos cães estavam infectados, enquanto pela PCR, 12 (8%) dos animais foram positivos com bandas aproximadas de 450 pares de base (pb). Foram observados 36 (24%) cães infestados com Rhipicephalus sanguineus ou com Amblyomma spp. As espécies de Amblyomma observadas foram A. cajennense (25%) e A. ovale (25%). Não foi possível correlacionar a presença de R. sanguineus com a infecção por Babesia spp. O seqüenciamento de quatro amostras positivas demonstrou alta identidade com B. canis vogeli, já caracterizada no Brasil.

The status of Babesia spp. infection in dogs from rural areas of São Paulo State, Brazil was studied. For this, 150 animals were examined by blood smears and by PCR; the presence of tick infestation was also investigated. By the blood smear examination, 3 animals (2%) were detected positive and by PCR for Babesia spp. 12 (8%) were positive, with bands visualized in 450 bp. Rhipicephalus sanguineus or Amblyomma spp. were found on 36 (24%) of the 150 dogs. Amblyomma species found were A. cajennense (9/36-25%) and A. ovale (9/36-25%). It was not possible to correlate the presence of R. sanguineus and the infection with Babesia spp. The sequencing of four positive samples demonstrated close identity with B. canis vogeli already characterized in Brazil.

Pesquisou-se a presença de anticorpos contra Borrelia burgdorferi latu sensu em cães de áreas rurais de sete municípios do Estado do Rio de Janeiro, pelo ensaio imunoenzimático indireto, associando-se os resultados com a presença de carrapatos nestes animais. De 199 cães examinados, 15,58% estavam positivos, com títulos que variaram de 400 (13,57%) a 1600 (0,5%). Os casos positivos se distribuíram uniformemente nos sete municípios. Não houve diferença estatística (P > 0,05) de soropositivos entre as faixas etárias dos cães acima de seis meses. Carrapatos foram encontrados e coletados em 71 (35,68%) cães, dos quais 24,1% estavam infestados com Amblyomma cajennense, 13,6% com Rhipicephalus sanguineus, 2,5% com Amblyomma aureolatum e 1,5% com Amblyomma ovale. Dos animais soropositivos para B. burgdorferi, 38,7% apresentavam A. cajennense e 22,6% apresentavam R. sanguineus, não havendo, entretanto, correlação positiva entre a presença do carrapato e sorologia positiva.

The prevalence of antibodies against Borrelia burgdorferi latu sensu was investigated in dogs from rural areas of seven towns of the Rio de Janeiro State, Brazil, using an indirect enzyme-linked immunosorbent assay. All dogs were also examined for the presence of ticks. From the 199 dogs, 15.58% were seropositive, with titers that ranged from 400 (13.57%) to 1600 (0.5%). The positive cases were equally distributed among the seven studied towns. No differences (P > 0.05) were found among the age groups of over six months old. Ticks were found and collected from 71 (35.68%) dogs. From this total, 24.12% were infested with Amblyomma cajennense, 13.6% with Rhipicephalus sanguineus, 2.5% with Amblyomma aureolatum and 1.5% with Amblyomma ovale. Amblyomma cajennense was found in 38.7% and R. sanguineus in 22.6% of the dogs with B. burgdorferi antibodies, although no positive correlation between the ticks parasitism and positive serology was found.

Hepatozoon species are the most abundant hemoparasites of snakes. Its identification has been based mainly on the morphologic characterization of the gamonts in the peripheral blood of the vertebrate host and also of the cysts found in the internal organs of the vertebrate and invertebrate hosts. Using a computerized image analysis system, we studied five species of Hepatozoon from recently captured snakes in Botucatu, State of São Paulo, Brazil, to evaluate the importance of the morphology and morphometry of the gamonts for the characterization of Hepatozoon species and to analyze the morphologic changes induced in the erythrocytes by the parasite. The studied species were H. terzii of Boa constrictor amarali, Hepatozoon sp. of Crotalus durissusterrificus, H. philodryasi of Philodryas patagoniensis, and H. migonei and H. cyclagrasi of Hydrodynastes gigas. We observed three different groups, one of them including the species H. terzii, H. philodryasi and Hepatozoon sp. of C. durissus terrificus; and the other two consisting of H. migonei and H. cyclagrasi. Degree of alterations in the erythrocytes was variable and it may be useful for characterization of Hepatozoon species.