Rangelia Vitalii (Carini, 1908) (Apicomplexa, Piroplasmorida) in domestic dog in southern Brazil: a case report

Rangeliosis is an extravascular hemolytic disease caused by the piroplasm Rangelia vitalii. This protozoan is transmitted by ticks of the species Amblyomma aureolatum and infects erythrocytes, endothelial cells, and leukocytes, leading to a variety of clinical signs such as anemia, thrombocytopenia, splenomegaly, hepatomegaly, jaundice, and bleeding from the nose, oral cavity, and ear tips. This study aims to report a case of rangeliosis in a domestic dog in southern Brazil. A female, adult, mixed-breed dog from a rural area was admitted to a Veterinary Hospital. Clinical examination revealed necrosis of the ear tips with active bleeding and abdominal hematomas. After a few days, the patient also developed jaundice, hematuria, bilirubinuria, subconjunctival hemorrhage, and epistaxis. Hematological analysis indicated anemia and thrombocytopenia, while biochemical tests revealed elevated serum urea levels. The definitive diagnosis was confirmed through a stained blood smear, which revealed the presence of R. vitalii inside leukocytes and free in plasma. In addition to supportive treatment, doxycycline and imidocarb dipropionate were administered. However, due to disease progression, the patient ultimately succumbed. Canine rangeliosis is likely an underdiagnosed disease; therefore, it is crucial to consider it as a differential diagnosis in patients presenting compatible clinical manifestations and laboratory findings, particularly in those from rural or forested areas or with access to such environments.