Haemoprotozoan and haemorickettsial carrier status in pet and community owned dogs of south India.

The increasing population of dogs and changes in the climatic conditions have resulted in the emergence and re-emergence of vector-borne diseases in canines. These vectors borne diseases in canines pose a diagnostic challenge to the field veterinarians because of co-infections with several pathogens. Comprehensive data on the prevalence of haemoparasites and haemorickettsiales in pet and community owned dogs from south India are scant. Hence, the present study aims to find and compare the prevalence of these infections in the pet and the community owned dogs of Kerala, a south Indian state. Two hundred and seventy-two pets and 150 community owned dogs were examined by microscopy and polymerase chain reaction (PCR) for infections with different heamoparasites and haemorickettsials from January 2018-November 2020 in the state of Kerala. A high prevalence of Babesia gibsoni infection (42.2-60.0 %) in pet and community owned dogs, followed by Babesia vogeli (5.8-39.3 %), Hepatozoon canis (0.7-28.0 %), Trypanosoma evansi (0.0-27.3 %), Ehrlichia canis (0.3-0.6 %) and Anaplasma platys (0.0-0.6 %) was observed in the present study. Eighty-eight per cent (132/150) of the community owned dogs and 49.2 % (134/272) of the pet dogs were positive for at least one pathogen. Phylogenetic analysis based on the partial nucleotide sequences of 18S rRNA and TRAP gene of B. gibsoni, 18S rRNA genes of B. vogeli and H. canis and RoTat, 1.2 virB9 and 16S rRNA genes of T. evansi, E. canis and A. platys, respectively was carried out. B. vogeli, H. canis, E. canis and A. platys revealed genetic relatedness between the Indian isolates and the isolates from other countries. However, B. gibsoni isolates from the Indian sub-continent were genetically unique compared to other Asian isolates. The clustering of T. evansi isolates from India in two clades viz., livestock origin (cattle, buffalo) and others indicated their genetic variability. The present study summarizes the prevalence of some of the haemoparasites and haemorickettsials in the dog populations of Kerala (south India) and also determined their genetic relationship with the isolates prevalent in dogs in other countries.