Efficacy of Azithromycin and Atovaquone Combination Therapy in the Clinical Management of Babesia gibsoni Infection in Dogs

Abstract

Six dogs with clinical babesiosis were presented at the Veterinary Clinical Complex, Rajendranagar, Hyderabad. Breeds affected were Labrador Retriever (2), German Shepherd, Belgian Malinois, Golden Retriever, and one non-descript (n=6). Young dogs (<4 years) predominated (83.33%), and males were more affected (66.67%), possibly due to fight-related bite transmission of Babesia gibsoni in addition to ticks. Common clinical signs included fever (100%), anorexia and pale mucous membranes (83.3% each), lethargy and lymphadenopathy (66.7% each), splenomegaly and hemoglobinuria (50% each), and icterus (33.3%). Hematological findings revealed regenerative anemia, consistent thrombocytopenia (100%), and leukocytosis. Biochemical alterations included hyperbilirubinemia, elevated liver enzymes (ALT, AST, ALP), hypoalbuminemia, hyperglobulinemia, and mild azotemia in some cases. Giemsa-stained blood smears confirmed small intraerythrocytic B. gibsoni piroplasms in all dogs. Ultrasonography showed splenomegaly (50%), hepatomegaly, and increased renal echogenicity in affected cases. All dogs were treated with atovaquone (13.3 mg/kg TID) and azithromycin (10 mg/kg SID) for 10 days along with supportive therapy. Clinical recovery occurred within 7-10 days, with complete hematological improvement and negative blood smears by day 30. The study highlights the characteristic hemolytic anemia, thrombocytopenia, and multisystem involvement in canine B. gibsoni infection, along with excellent therapeutic response to the atovaquone–azithromycin protocol.