A two year old boxer who has never left the province of Ontario has been diagnosed with an infection of Echinococcus multiocularis.
Prior to 2009, the only cases of Echinococcus multilocularis described in dogs in North America were seen in Alaska; the 2009 case was in British Columbia.
Echinococcus multilocularis is a tiny tapeworm usually found in the small intestines of foxes & coyotes. The eggs in the animals’ feces are picked up by rodents, where they develop into an intermediate stage & cause alveolar hydatid cysts in the liver that are ultimately fatal. When foxes or coyotes eat these rodents, the adult tapeworm develops & the cycle continues. The parasite can also infect dogs and cats if they eat rodents.
This parasite poses a significant health risk to humans: if people ingest the parasite’s eggs they may develop the intermediate stage in the liver, which has a high mortality rate if left untreated.
The Ontario boxer most likely consumed a “massive number of eggs” from coyote or fox feces. Since then, two more dogs have been diagnosed in southern Ontario. Neither of these dogs have traveled outside of the province.
To date, no human cases have been reported in Ontario. It should be noted that it takes 5 to 15 years for clinical signs to develop in humans, meaning there could be people infected but not yet diagnosed. The people in contact with the 3 Ontario dogs have tested negative. Cases in dogs could be missed because the infection in the liver looks very much like a tumor.
Veterinarians are being urged to be aware of this emerging disease. Bayer Canada is assisting veterinarians with diagnostic testing for dogs with suspicious abdominal lesions. Public Health Ontario & other groups are working on further research & prevention strategies.
This link will take you to an hour long video titled Echinococcus Multilocularis: Emerging Public Health Issue in Canada? (edited version)