Giant Red Kidney Worm (Dioctophyma renale) Screening and Treatment Protocol and Aberrant Worm Migration In Dogs From Ontario and Manitoba, Canada.

The life cycle of Dioctophyma renale involves an intermediate host (oligochaete), a paratenic hosts (fish and frogs), and a definitive host (mustelids and canids). Dogs are at risk of infection with D. renale when they consume paratenic hosts infected with the larval form of D. renale. Water containing the oligochaete intermediate host cannot be disregarded as another source of infection. Infections occur mainly in the right kidney, but worms have also been found in the abdominal cavity as well as other organs. Most dogs appear asymptomatic and infections are usually noted as incidental findings on necropsy. Recently, the Ontario Society for the Prevention of Cruelty to Animals (SPCA) and Humane Society conducted transports of dogs located in northern remote communities. In 2016, some female dogs were found to be infected with D. renale upon ovariohysterectomy. In response to this discovery, we developed a screening protocol to screen for D. renale infections. In 2018, a total of 130 intact dogs were transferred from 2 northern communities in the provinces of Ontario and Manitoba. A prevalence of 7.94% (95% confidence interval 3.87-14.11%) was found from dogs from the northern communities. The screening protocol we developed provides a method of screening for dogs that are transported from communities that could be at risk of infection with D. renale.