General Information

Echinococcus multilocularis is a wildlife associated tapeworm. The adult tapeworm is normally found in the small intestine of foxes and coyotes but can also be found in dogs and less commonly cats. Eggs are shed in the feces of an animal infected with the adult stage of the parasite. Infection with the intermediate stage is transmitted to people through ingestion of tapeworm eggs and can result in a disease called alveolar echinococcosis.

Photo by: Steph Kelly

Photo by: Jeremy Tozzi

Life cycle

Echinococcus multilocularis and dogs

It is important to know that dogs can be both definitive hosts as well as accidental hosts. Both types of infection are very different:

Liver Infection

alveolar echinococcosis
intermediate stage in liver
causes tumour-like growths in the liver
dogs must eat a large numbers of eggs (e.g. ingestion of coyote or fox feces)
no eggs are shed
detrimental to dog's health

Intestinal Infection

dog appears healthy
adult tapeworms in small intestine
dogs must eat an infected rodent
shed eggs in their feces
can be prevented by monthly deworming treatment

Reportability

Since 2012, six cases of alveolar echinococcosis (AE) have been diagnosed in domestic dogs residing in Ontario; five lived in areas around the western end of Lake Ontario. This is a concern since five of the six dogs had not left the province, suggesting they acquired the infection locally. Additionally, cases of AE have been diagnosed in three lemurs and one chipmunk in the same region (Turner et al. 2016; French et al 2018). As a result of these data and others, E. multilocularis was made reportable in all animal species in Ontario in January 2018 (R.R.O. 1990, Reg. 557). In July 2018, E. multilocularis infection in people in Ontario was designated a disease of public health significance (Ontario Regulation 135/18).

References:

Ontario Regulation 135/18 (Designation of Diseases) under the Health Protection and Promotion Act. (https://www.ontario.ca/laws/regulation/180135)

Turner PV, Compo NR, Davidson S, McDowell R, Cai H, Gottstein B, Peregrine AS. Diagnoses of alveolar echinococcosis in Lemurs at an exotic animal sanctuary: implications for public health. 66th Annual Meeting of the The James Steele Conference on Diseases in Nature Transmissible to Man (DIN), 25th-27th May 2016, San Antonio, Texas, U.S.A.

R.R.O. 1990, Reg. 557 (Communicable Diseases - General) under the Health Protection and Promotion Act. (https://www.ontario.ca/laws/regulation/900557)