Coinfection with Trypanosoma evansi and Hepatozoon felis in a free-ranging jaguar (Panthera onca) in the Pantanal biome, Brazil.

Coinfection with Trypanosoma evansi and Hepatozoon felis represents a rare occurrence in wild felids, with no previous reports in Panthera onca. A free-ranging adult male jaguar weighing approximately 70 kg was examined after being rescued from wildfires in the Brazilian Pantanal (Corumbá, Mato Grosso do Sul). The initial hematological evaluation (D0) revealed mild anemia (PCV: 27.7%; reference: 30-45%), with Trypanosoma spp. trypomastigotes forms detected by direct microscopy. Treatment with diminazene aceturate (3.5 mg/kg, IM) was instituted on D1. On D5, microscopy revealed Hepatozoon felis gamonts within leukocytes, characterizing coinfection. Molecular analysis by PCR confirmed the presence of both agents in the D0 sample, with amplification products of approximately 600 bp (Hepatozoon spp.) and 196 bp (T. evansi), validating the microscopic diagnosis. Despite treatment and the absence of microscopically detectable parasitemia on D12, anemia persisted (PCV: 21.7%). The animal progressed to death on D19 during sedation for wound management. At necropsy, severe pulmonary involvement (bronchiolitis, alveolitis, and endogenous lipid pneumonia) compatible with smoke inhalation injury was observed. These findings highlight the importance of integrating hemoparasite surveillance into rehabilitation and conservation protocols for threatened felids in fire-affected ecosystems.