Prevalence of vector-borne pathogens Ehrlichia canis, Babesia spp. and Dirofilaria immitis in dogs in Townsville, far north Queensland.

Abstract

Ehrlichia canis, Babesia spp. and Dirofilaria immitis are blood-borne pathogens transmitted to dogs by arthropods. The aim of the current study was to investigate the prevalence of E. canis, Babesia spp. and D. immitis in domestic dogs, aged 6 months or older, in Townsville, in far north Queensland, Australia. Dogs were recruited through convenience sampling, with the assistance of local veterinary clinics and James Cook University staff and students. Up to 3 ml of blood was collected per dog, into EDTA vacutainer tubes. Testing for E. canis and Babesia spp. was performed through qPCR, with a second PCR used to identify the species in Babesia-positive cases. Testing for D. immitis was performed using a commercial antigen detection kit and the modified Knott's test (MKT); microfilariae identity was confirmed by morphological features and qPCR. Of 301 dogs sampled, none tested positive for E. canis, whereas 9 (3.0%, 95% CI 1.1-4.9%) tested positive for Babesia vogeli, and 15 (5.0%; 95% CI 2.5-7.5%) tested positive for D. immitis, based on the combined antigen and MKT results.