April 28, 2026
UW study finds disease-causing tapeworm in Washington coyotes
A ÁñÁ«ÊÓƵ study has found the parasitic tapeworm Echinococcus multilocularis, which can infect dogs and humans, in more than one‑third of coyotes tested in the Puget Sound region, marking the first detection of the parasite in a wild host on the contiguous U.S. West Coast.
Previously rare in North America, the tapeworm has been spreading for about 15 years and can cause severe, potentially fatal disease characterized by cancer‑like cysts in the liver. While coyotes can carry the parasite without becoming sick, humans and dogs are accidental hosts who may develop illness years after exposure.
Researchers emphasize that although human cases remain very rare, awareness and preventative measures, especially for dog owners, are important now that the parasite is established in Washington.