The Echinococcus granulosus tapeworm is found almost worldwide in canids, including wolves, dogs, coyotes, and foxes. The eggs of this tapeworm are spread in canid feces.
Wild and domestic ungulates (deer, elk, moose, sheep, goats, swine, etc.) are the normal intermediate hosts, carrying a cyst form (called a hydatid cyst) in their organs. When canids (including dogs) feed on these infected organs, they become tapeworm hosts. (For tapeworm life-cycle information, and recent research on this topic, see the CDC's Echinococcosis website.)
Humans are very rarely affected, because they would have to ingest tapeworm eggs in canid feces or drink water contaminated with canid feces to become infected. The parasites are highly unlikely to be spread by handling ungulate capes or meat, unless those parts are contaminated with canid feces and handlers do not use good basic hygiene. Likewise, if a pet dog rolled in feces infected with tapeworm eggs, good hygiene is required after handling the dog.
Humans cannot be infected by ingesting cysts found in ungulates. These parasitic tapeworms are not wind-borne nor transmitted to humans in any way other than direct ingestion of eggs in feces.
All parasites or diseases harbored by any wildlife should be taken seriously. Good hygiene should always be used when handling live wild animals, dead wild animals, their secretions, or their products. Specifically:
- Wear disposable gloves when field dressing, skinning and butchering game.
- Cut away any fibromas, cysts, or other growths, which are common but usually don’t affect game meat quality.
- Wash hands and clothes with soap and water after handling game.
- Clean your hunting knife and other utensils often with clean water and soap.
- Do not let dogs eat organs or scraps from hunter harvested or road killed animals.
- Consult with your veterinarian about a parasite control program for your pets.
- Do not handle animals that are found dead or carnivore feces; if handled, wash hands and clothes.