The Coyote Tapeworm

In the last few days, we have been fielding a lot of questions about the coyote tapeworm from concerned dog owners. Should they worry? What should they do? Here’s a little bit of information to help you understand.

The coyote tapeworm is Echinococcus multilocularis and has been diagnosed in a small number of dogs in Ontario since 2012. Recently it has been discovered that this tapeworm is present in about 25% of wild canids (foxes, coyotes). Much higher than previously thought. The infection was concentrated most heavily in the western-central part of the province.

Usually, tapeworm infection isn’t a problem because the intestinal form of echinococcus does not make these animals sick. In the normal life cycle of the tapeworm, wild canids shed eggs in their feces, and these eggs are eaten by small rodents, which develop parasitic cysts in their body. When a canid eats the infected rodent, the life-cycle continues, and the parasite grows into the adult stage in the gut then produces more eggs.

Occasionally, however, when something (or someone) eats tapeworm eggs, it can lead to a different form of infection called alveolar echinococcosis (AE). In this form, tumour-like cysts form in various parts of the body, particularly the liver, and can be very challenging to treat by the time it is diagnosed.

Pet dogs that eat feces of foxes or coyotes or rodents (dead or alive) are at risk. These dogs can pass the infection onto their owners. Owners who let their pet sleep in their beds are most likely to ingest the microscopic eggs accidentally.

Dogs that might have contact with wild canid feces or are prone to eating small rodents should be dewormed regularly. Contact your veterinarian for appropriate drug choices based on your dog’s lifestyle. And always practice good hygiene when handling pet feces. Protect your hands from coming in contact and wash immediately afterwards.

Written by: Jennifer Merry BSc (Agr) DVM