Clinical and hematological evaluation of Rangelia vitalii-naturally infected dogs in southeastern Brazil

Abstract Rangelia vitalii, a tick-borne piroplasm that infects dogs, has been recently molecularly characterized in Brazil, Uruguay and Argentina. Studies on molecular characterization of these piroplasms in different Brazilian regions are scarce. The aim of this study was to evaluate clinical and hematological changes in dogs caused by R. vitalii in the mountainous region of the state of Rio de Janeiro. Blood samples from 36 dogs were evaluated for piroplasms and hematological disorders using light microscopy and molecular analysis. Blood samples from all the animals included in this study were confirmed to be positive for R. vitalii through genetic sequencing. Clinical signspresented by 24 of the 36 dogs of the study were evaluated during appointments or hospitalization within private practice. The most frequent clinical disorders in these dogs that were naturally infected with R. vitalii were fever, spontaneous cutaneous bleeding and diarrhea. Normochromic non-regenerative anemia and thrombocytopenia were the most common hematological disorders in these R. vitalii-positive dogs and therefore should be considered in hematological evaluations on suspected cases.

摘要：兰氏巴贝虫（Rangelia vitalii）是一种感染犬只的蜱传梨形虫，近期已在巴西、乌拉圭与阿根廷完成分子生物学鉴定。目前针对巴西不同地区此类梨形虫的分子生物学特征研究较为匮乏。本研究旨在评估里约热内卢州山区犬只感染兰氏巴贝虫后引发的临床与血液学变化。本研究通过光学显微镜与分子分析技术，对36只犬的血液样本开展梨形虫与血液学异常检测。本研究纳入的所有受试动物血液样本，均经基因测序确认兰氏巴贝虫检测结果呈阳性。本研究中36只受试犬中的24只，其出现的临床症状在私人执业诊所的就诊或住院期间被评估记录。自然感染兰氏巴贝虫的受试犬最常见的临床病症为发热、自发性皮肤出血与腹泻。正色素性非再生性贫血与血小板减少症是兰氏巴贝虫检测阳性犬只最常见的血液学异常，因此在疑似病例的血液学评估中应将此类异常纳入考量。