K9 Tapeworm Study (2015 - 2017)
Echinococcus multilocularis has an extensive range in the northern hemisphere, including: central Europe, most of northern and central Eurasia, and parts of North America. In North America, the range of the parasite is thought to include the majority of the Canadian Arctic as well as the southern portions of Alberta, Saskatchewan, and Manitoba, along with 13 neighbouring US states.
Prior to 2012, E. multilocularis had never been diagnosed in Ontario. Since then, six dogs, three non-human primates, and a chipmunk have been diagnosed with alveolar echinococcosis. Five of the six dogs and all of the non-human primates had not traveled outside southern Ontario, which suggests they acquired the infection locally.
Since humans and domestic dogs can develop alveolar echinococcosis, there is now an urgent need to determine where in Ontario these animals likely became infected, and the potential risk areas for future infections in Ontario. Such information is required by both the public health and veterinary communities. Approximately one-third of the Canadian human population lives in southern Ontario. Furthermore, domestic dogs are of particular concern since they live in close proximity to humans, allowing for potential transmission of infection to humans by shedding of eggs in feces if they have an intestinal infection. Fortunately, to date, no human case has been detected in Ontario.
What has been done?
Researchers at the Ontario Veterinary College at the University of Guelph conducted a study from 2015-2017 determine how common E. multilocularis is in foxes and coyotes across southern Ontario. This study aimed to answer the following questions:
(1) How common is E. multilocularis among wild coyotes and foxes, and where is it located in southern Ontario?
(2) What are the high-risk areas of infection in southern Ontario for dogs and people?
(3) What factors increase the chance of a wild coyote or fox getting infected with E. multilocularis?
What was found?
From 2015-2017, the research team tested 460 foxes and coyotes from across southern Ontario for E. multilocularis. Surprisingly, 23% were positive for this parasite from across southern Ontario (Figure 1), with infection concentrated most heavily in the western-central part of the region.
What is left to do?
Research is still ongoing to determine the factors that increase the chance of a wild coyote or fox getting infected with E. multilocularis.
Kotwa JD, Isaksson M, Jardine CM, Campbell GD, Berke O, Pearl DL, Mercer NJ, Osterman-Lind E, Peregrine AS, (2019). Echinococcus multilocularis Infection, Southern Ontario, Canada. Emerging infectious diseases, 25(2), 265.
Figure 1. Distribution of Echinococcus multilocularis infection in wild canids across southern Ontario, 2015-2017. The prevalence of infection is organized by the 29 southern Ontario public health units.