Echinococcus Granulosus Found in Maine Moose
Over the last three years the Department of Inland Fisheries and Wildlife has been collaborating with the University of Maine Animal Health Lab in examining the presence of lungworms (Dictyocaulus spp.) in moose. Lungworms have been noted in moose that have been found dead in late winter with heavy winter tick loads and the combination of both parasites has been implicated as a cause of calf mortality.
This past fall, students once again increased sampling intensity of moose lungs from harvested animals. This led to the University of Maine-Animal Health Lab finding Echinococcus granulosus (E.G.) cysts in some moose lungs. EG is a very small tapeworm that has a two part lifecycle; one in canids (coyotes/foxes/domestic dogs) and the second in moose. There are several known genotypes of this tapeworm, and genetic testing of the Maine tapeworms found that this EG is the northern, or least pathogenic, form. Although Echinococcus granulosus can infect humans, the form that is known to do so most often is the sheep-dog genotype. Finding the northern, wild-type form of EG in moose in Maine suggests that likely wild canids in Maine are infected and that possibly domestic dogs are infected as well, and that fact may allow for human exposure to this parasite. It is also very likely that we have coexisted with these tapeworms for years with no apparent problems having not actively looked for them prior to this work.
The adult tapeworm lives in the intestines of the canid host, while the larval form lives in the lungs or liver of an infected moose. Humans may become infected by ingesting eggs of the parasite picked up by contact with canid feces.
In conjunction with the Maine Center for Disease Control and Prevention and University of Maine Animal Health Lab/Cooperative Extension, the Department recommends that people encountering dead wild animals be cautious. We offer the following suggestions including wearing rubber or latex gloves when field dressing game and thoroughly cooking any wild game meat that will be consumed. In addition we recommend protecting your pets through regular veterinarian visits and avoiding contact with dead wild animals. The Department of Inland Fisheries and Wildlife website has additional recommendations on its website www.maine.gov/ifw. The Department would reiterate that very likely we have coexisted with these tapeworms for years with no apparent problems.
