Fatal coinfection with Hepatozoon canis, Babesia vogeli, Ehrlichia canis, and Bartonella clarridgeiae in a dog from Argentina.

Vector-borne diseases represent a growing global threat, exposing new populations to previously unknown infectious agents, and posing diagnostic challenges for veterinarians. The aim of this article is to present a clinical case of coinfection with different hemoparasites in a canine with severe ectoparasite infestation and clinical signs of shock. Blood smears and complete necropsy were performed. Samples of different organs were obtained for histopathological and molecular biology studies. Examination of the blood smears showed azurophilic intracytoplasmic structures, compatible with the morphology of Ehrlichia canis, monocytes with the presence of gametocytes inside neutrophils, compatible with infection with Hepatozoon canis, and pyriform intraerythrocyte structures compatible with large piroplasms. Acridine orange staining, performed on different histological sections, allowed visualizing textures on fluorescent microscopy analysis, which were morphologically compatible with Bartonella sp. Molecular tests were positive for Ehrlichia spp., Hepatozoon spp., Babesia spp. and Bartonella spp. Control of vector-borne diseases would improve the health and well-being of animals and humans, especially in developing countries in the tropics, where the risk of contracting these diseases is high and access to health care is poor. Vector-borne diseases should always be suspected and included in the differential diagnosis, especially in areas with the presence of ticks and fleas.