September 25, 2023

Confirmed: Maine Moose Carry Echinococcus Granulosus Tapeworm

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In a report that came out last week from meetings within the Maine Legislative Joint Standing Committee on Inland Fisheries and Wildlife, Lee Kantar, Maine Department of Inland Fisheries and Wildlife’s (MDIFW) head moose and deer biologist, was quoted as saying they had discovered the presence of a new “lung tapeworm” in moose examined in parts of northeastern Maine. The name of the tapeworm was not revealed at that time but I can confirm from an email I just received that this tapeworm is echinococcus granulosus. I can also report that this is not a good thing but nothing we should panic about – just get educated about.

Below is a press release made available by the MDIFW about the finding and precautions. I will follow this up with better and more details of the precautions that you should be taking to not contract, what in humans, becomes hydatid disease.

First the MDIFW press release:

Echinococcus granulosus in Maine Moose

Over the last three years 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 The Department would reiterate that very likely we have coexisted with these tapeworms for years with no apparent problems.

Maine people need to be educated about this potential health hazard. I am writing from several years experience in researching and writing about this disease. In educating people, it should not be taken as some kind of attack against coyotes/wolves, foxes, etc. It’s a nasty disease that can be spread quickly and easily but there are many things each of us can do to reduce the risks of infection. Deny there is danger is ignorant.

I will not spend a great deal of time now about this process but I would like to point out a few things that did not get covered in depth in this press release. But first, I have on this website an extensive amount of information about this tapeworm and hydatid disease. Please find that by clicking on the link at the top of the page under Wildlife Diseases and then click on E.G./Hydatid Disease.

The press release states this tapeworm was found in the lungs of moose. It must be explained that all ungulates, i.e. moose, deer, elk, etc. are common secondary hosts of the tapeworm. The results show up in large cysts found in many of these ungulate organs – lungs, liver, brain. While not deadly to the animal, it does restrict their breathing ability when amassed in the lungs and thus limits their ability to escape predators.

In humans, a contraction of the disease is known as hydatid disease and these cysts also can form in lungs, liver, brain, etc. It is not normally looked for by physicians and is difficult to diagnose. There are human cases of hydatid disease in this country. I have the documentation of that. Because of the difficulty in detection combined with lack of symptoms, a real danger becomes possible when a blow to the abdomen and a rupturing of these cysts resulting sometimes in Anaphylactic Shock and death. Therefore it is important to know what to do to reduce your chances of contracting this disease. Treatment is expensive and complicated.

There are many, many ways humans can contract this disease but let me first talk about the most serious one – from your family pets, i.e. dogs. In the press release it states that, “Humans may become infected by ingesting eggs of the parasite picked up by contact with canid feces.” More on the “ingestion” in another article.

If your dog free ranges or roams outside and even worse runs into pastures or the woods, you should stop allowing this immediately. Dogs are notorious for eating and rolling in dead carcasses. Eating a dead animal with the worms will allow your dog to get the worms. Make sure your pets are properly cared for and if you live in and near areas known to have echinococcus granulosus infected wild animals, let your vet know. However, the dog can easily bring these worms/parasites home to you and your children.

They roll in it and the parasites stick to their fur. They eat it and it gets in and around the mouth. The dog comes home and licks or plays with you or the kids and you unknowingly can ingest the parasite. The dog can leave them in carpets, rugs, furniture, bedding, etc. and the parasites remain viable for ridiculously long periods of time.

Coyotes/wolves often visit your home, even in town, during the nighttime hours and/or while you are away. Upon their visit, most often they will deposit a calling sign (feces) in your yard. If you or the children are outside, you can step in it and your dog being outside might decide to eat it or roll in it and the threat to you and your family is just as real.

I will cover more on this at a later time and please do not disregard the facts about this. There is nothing to necessarily be frightened about but precautions are a must. Some people will take offense at any indication on any degree of danger in this and dispute facts. They are there. My website contains pages of historical data from around the world on this disease. Please take note and be advised.

The press release stated that, “very likely we have coexisted with these tapeworms for years with no apparent problems.” I cannot concur with that statement nor will several parasitologist and wildlife experts I confer with on this disease. We may have lived with this tapeworm in such small amounts that to our knowledge we have not been affected. However, it must be noted that with a population of coyotes and wolves, expanding now in seemingly every landscape in this country, the odds of having problems has grown immensely. Infected coyotes/wolves can and do cover vast expanses of land and with it will spread this disease.