Haemoparasites of free-roaming dogs associated with several remote Aboriginal communities in Australia

Seventeen dogs (44%) were infected (PCR positive) with Mycoplasma haemocanis, eight (21%) with ‘Candidatus Mycoplasma haematoparvum’, 20 (51%) with A. platys, and 17 (44%) with B. vogeli. Two dogs were infected with a novel haemoplasma as determined by DNA amplification and sequencing. Two dogs (5%) were serologically positive for Dirofilaria immitis antigens, one (3%) was positive for Ehrlichia canis antibodies and nine (24nbsp;%) were positive for A. platys antibodies. Co-infections were frequent. Haemoplasma prevalence was highest (73%, 16/22) in Central Australia and lowest (22%, 2/9) in Western Australia (p？=？0.017). In contrast, B. vogeli prevalence was low in Central Australia (18%, 4/22) but higher (78%, 7/9) in Western Australia (p？=？0.003).This is the first time haemoplasma infections, including a novel species, have been molecularly documented in Australian dogs. The wide regional variation in prevalence of some of the haemoparasite infections detected in this study warrants further investigation.Dogs associated with the Aboriginal communities in the remote regions of Australia are considered to be free-roaming as they are owned but not confined in any manner. Amongst this canine population, infestation with the brown dog tick (Rhipicephalus sanguineus) is endemic and infections with Anaplasma platys and Babesia vogeli, tick-borne haemoparasites associated with R. sanguineus, are widespread [1]. The canine haemoplasmas Mycoplasma haemocanis and ‘Candidatus Mycoplasma haematoparvum’ are also believed to have R. sanguineus-mediated transmission [2], with free-roaming behaviour suspected of being a significant risk factor for the relatively high haemoplasma prevalence (20%) in Tanzanian dogs [3]. A recent PCR-based study of a canine hospital population in Sydney, New South Wales did not identify any haemoplasma infections (N. Hetzle, personal communication), although the blood was collected from non free-roaming owned dogs in a large city where the brown dog