Molecular identification of Babesia spp. in naturally infected dogs of Kerala, South India.

Canine babesiosis is a tick borne haemoprotozoan disease caused by large and small intraerythrocytic apicomplexan piroplasms of the genus Babesia spp. The clinical manifestations of the disease vary from inapparent subclinical form to hyperacute shock related haemolytic crisis. Microscopic examination of blood smears from suspected dogs revealed Babesia canis and B. gibsoni in 3.45 and 25.86 % of samples respectively. A seminested PCR based on previously published species specific primers targeting the 18S rRNA gene was utilized to identify the Babesia species infecting dogs of Kerala at the sub species level. The study revealed 57.5 % prevalence of Babesia spp. among dogs. This report also presents the first molecular evidence of Babesia canis vogeli and B. gibsoni among naturally infected dogs in Kerala, South India. Molecular survey revealed a high prevalence of B. gibsoni infections when compared with B. canis vogeli infections among canines of the state. Preliminary survey of the tick population revealed the presence of Rhipicephalus sanguineus, R. haemaphysaloides and Haemaphysalis bispinosa in infected animals. Further studies need be directed towards utilizing the PCR protocol for confirming the vectors of these species in the region.