Hematological alterations in large Babesia species infection in dogs of Kannur District of Kerala

Abstract

Canine babesiosis is a tick-borne disease caused by apicomplexan intraerythrocytic hemoprotozoan parasites. It is caused by the small (Babesia gibsoni, B. conradae, and B. vulpes) and large (B. vogeli, B. canis, and B. rossi) Babesia groups. As per the recent reports, the most prominent Babesia species encountered in the Kerala state are the small Babesia, B. gibsoni followed by the large Babesia, B. vogeli. The latter is regarded as mildly pathogenic, causing subclinical or mild disease; however severe complications like systemic inflammatory response syndrome, multiple organ dysfunction syndrome, etc. have also been reported. The information on the status of hematological alterations in naturally infected dogs with large Babesia is lacking, particularly from the state of Kerala. The present study involves a retrospective study of clinical cases of large Babesia infection in dogs. The complete haematological profile from well-documented laboratory records of 4039 dogs suspected for babesiosis presented to District Veterinary Centre, Kannur during the period from December 2018 to October 2020 was analyzed for the study. Natural infections were recorded in 35 (0.87%) dogs based on the presence of intraerythrocytic piroplasm of large Babesia spp. by light microscopic examination of Giemsa-stained blood smears. The most consistent features observed were mild to moderate regenerative, normocytic and normochromic anemia, lowered to normal neutrophil count and thrombocytopenia. In comparison to hemolytic anemia, thrombocytopenia was the most frequent clinicopathological finding in the study with an increased presence of large activated platelets or macro-platelets.