A new parasite, Echinococcus multilocularis, seems to be establishing in Ontario. Reports of infections are still rare but more cases are being reported.
Echinococcus multilocularis is a small tapeworm that can cause severe disease.
Dogs and wild canids such as foxes are the definite hosts, shedding tapeworm eggs in the feces. Normally it's small rodents, who has eaten the infected feces that get ill and develop tumor-like lesions containing the immature parasite. Canids then get infected by eating small rodents ...
Normally this parasite should not be a problem for the dogs.
In the intestine, the parasite doesn't cause any trouble. But as it seems, dogs now can develop the same disease as rodents, having the infections outside the intestines, such as in the liver.
More Ontario Echinococcus multilocularis cases
Update on Echinococcus multilocularis in Ontario