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Public Health - Seattle & King County

Diseases from raccoons and other wildlife



Raccoons have adapted to urban life and are commonly seen or encountered by King County residents in parks, neighborhoods or yards. Raccoons may carry diseases that can be spread to people (zoonoses) and pets. These diseases include the raccoon roundworm, leptospirosis, and rabies. Raccoons can also cause serious scratch and bite injuries to people and pets.

Raccoons establish community latrines -- sites where they repeatedly deposit fresh feces that are very likely to contain roundworm eggs that can be hazardous to human health. Once deposited in the environment, the eggs develop into the infectious form in 2-4 weeks, and can survive in the soil for several years. If these infectious eggs are inadvertently swallowed by humans, the larvae (immature stage of worms) hatch out of the eggs and may move into the organs of the body causing serious disease. Young children are most at risk. Learn more about diseases from raccoons.


Leptospirosis is a disease caused by bacteria called Leptospira that infects both humans and a wide range of animals. It occurs worldwide but is more common in temperate and tropical areas of the world. Some people infected with leptospirosis will have no symptoms at all, and some people will become severely ill. Some wild and domestic animals, such as cattle, pigs, dogs, raccoons, and rodents, carry the Leptospira bacteria and pass them in their urine. Soil or water contaminated with infected urine are the most common causes of human infection but the disease can also be transmitted by direct contact with urine from an infected animal. Washington State has experienced an outbreak of leptospirosis in dogs over the past 5 years, with the majority of cases occurring in King County and neighboring areas. The disease can have a high fatality rate in dogs but early diagnosis and treatment improves the chances for recovery.

Raccoon roundworm (Baylisascaris infection)

Baylisascaris, an intestinal raccoon roundworm, can infect a variety of other animals including humans. Symptoms of infection in people depend on how many eggs are ingested and where in the body the larvae migrate (travel to). Once inside the body, eggs hatch into larvae and cause disease when they travel through the liver, brain, spinal cord, or other organs. Ingesting a few eggs may cause few or no symptoms, while ingesting large numbers of eggs may lead to serious symptoms. Symptoms of infection may take a week or so to develop. If a person is suspected of having swallowed soil contaminated by raccoon droppings, consult a health care provider immediately as preventative medication may be indicated. Be sure to report the concern about recent exposure to raccoon feces to your doctor.

Raccoons and rabies prevention

Raccoons carry rabies in many parts of the U.S. In a typical year, over 2,500 raccoons nationwide are reported with laboratory-confirmed rabies. Fortunately, Washington State has not had a documented rabies case in a raccoon. However, rabies in raccoons remains a concern as infected animals could be illegally or accidentally brought in from other states or a raccoon could get rabies from an infected bat. Raccoon bites to people must be reported to Public Health for evaluation of rabies risk. Protect pet dogs, cats and ferrets by vaccinating them against rabies. Do not attract raccoons by feeding them or allowing them access to pet food, garbage cans or other food sources. It is illegal to keep raccoons as pets in this and most other states.

Wildlife resources

  • Contact an experienced wildlife control service for help cleaning up latrines and removing problem raccoons. Refer to the directory of Nuisance Wildlife Control Officers trained and regulated by the Washington Department of Fish and Wildlife.

  • King County: If You Care, Don't Feed Us
    This downloadable brochure describes the health risks of feeding wildlife such as raccoons. Neighborhood solutions to wildlife problems are emphasized.

  • WA Dept of Fish and Wildlife: Living with Wildlife series
    Washington Department of Fish and Wildlife (WDFW) hosts a series of informational handouts about wildlife. You can find information about raccoons, pigeons, rats, crows, squirrels and many other wild animals. You can also access information about how locate a wildlife rehabilitator and how to hire a wildlife control company.