Seattle coyotes carry parasite that infects dogs
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Urban coyote alert. Photo: Mark Rightmire/MediaNews Group/Orange County Register via Getty Images
A disease-causing tapeworm that can infect dogs — and sometimes humans — has been found in more than a third of coyotes in the Puget Sound region.
Why it matters: In rare cases, this parasite can cause a serious, slow-growing disease in humans and dogs that forms tumor-like cysts in the liver and can be fatal if untreated.
- Symptoms typically take years to appear, complicating diagnosis.
- Treatment is possible but complex, often involving surgery and years of medication, even when caught early, according to the Centers for Disease Control and Prevention.
- The risk is low, but the potential consequences are severe.
Driving the news: The tapeworm to watch, Echinococcus multilocularis, was found in 37 of 100 coyotes surveyed in the Puget Sound region, according to a University of Washington study published last month in PLOS Neglected Tropical Diseases.
- The parasite has been spreading across North America for about 15 years. But this is the first detection of it in a wild host on the West Coast, according to the study.
Catch up quick: Coyotes are a routine part of Seattle's urban ecosystem, and this discovery adds a new public health risk just as spring pup season makes them more visible, territorial and prone to encounters with pets.
- Chase Gunnell of the Washington Department of Fish & Wildlife tells Axios that more coyote sightings — and reports of them following people near dens while raising pups — are common from March through May.
What they're saying: "There have been numerous cases of dogs getting sick, and a handful of people have also picked up the tapeworm," said the study's lead author, Yasmine Hentati.
- "The fact that we found it here in one-third of our coyotes was surprising, because it wasn't found anywhere in the Pacific Northwest until earlier this year."
How it works: E. multilocularis lives in rodents and in canines like foxes, coyotes and domestic dogs, which spread it through their feces. If its eggs are ingested, it can cause alveolar echinococcosis — a rare disease that forms tumor-like cysts in the liver, per the CDC.
- Humans or dogs and cats can be exposed through contaminated soil, food or surfaces.
- Infection can lead to serious liver disease that can be fatal if untreated.
Reality check: Human infections are very rare in the U.S., and only a handful of dog cases have been reported in Washington and neighboring states in recent years, according to the UW study.
What to do: To prevent conflict and contact with potentially infected coyotes, keep dogs leashed in parks and greenbelts, the Department of Fish & Wildlife advises.
- Prevent them from eating feces, rodents or carcasses.
- Stay current on deworming and routine vet care.
- And never feed coyotes.
The bottom line: Seattle's coyotes aren't new — but what they're carrying is, and it's a reason for smarter habits as encounters increase this spring.