Ticks are present in Washington State, inhabiting various natural environments including forests, grasslands, and suburban areas. Understanding where they live, common species, and potential health risks helps individuals safely navigate outdoor activities.
Common Tick Species in Washington
Washington State is home to several tick species, with three commonly encountered by humans. The Western Blacklegged Tick (Ixodes pacificus) is small, reddish to black, and has distinct dark legs. Females possess a reddish body with a black dorsal plate, while males are uniformly brownish-black and slightly smaller. This species is often found in forested or brushy regions.
The Rocky Mountain Wood Tick (Dermacentor andersoni) is reddish-brown and larger than the Western Blacklegged Tick. It shares a similar appearance with the American Dog Tick. These ticks primarily inhabit woodlands and grassy shrub areas.
The American Dog Tick (Dermacentor variabilis) is brownish-tan with marbled white or yellow markings on its back before feeding, becoming grayish-blue or olive green when engorged. Its body is oval-shaped, becoming rounder after a blood meal. Soft ticks (Ornithodoros genus) are also present, often associated with rodent nests in mountainous regions.
Where Ticks Reside in Washington
Ticks are distributed throughout Washington State, commonly residing in wooded areas, tall grasses, and brush. This includes hiking trails, forest edges, and urban/suburban parks, especially where wildlife like deer are present.
The Western Blacklegged Tick is primarily found in western Washington and along the eastern slopes of the Cascade Mountains, favoring forested and brushy environments. The Rocky Mountain Wood Tick and American Dog Tick are more common in eastern Washington, preferring woodlands, medium-height grasses, and sunny, open areas near woods. Ticks typically wait on low-lying vegetation to attach to passing hosts.
Health Risks from Washington Ticks
Ticks in Washington can transmit various pathogens that cause human diseases, though cases are relatively low compared to other states. Lyme disease, caused by the bacterium Borrelia burgdorferi, is transmitted by the Western Blacklegged Tick. Symptoms often include a characteristic “bull’s-eye” rash, fever, headache, and muscle or joint pain, with later stages potentially affecting joints, the heart, and the nervous system. While most Lyme disease cases in Washington residents are acquired out-of-state, a small number of local transmissions occur, primarily in western Washington.
Anaplasmosis, caused by Anaplasma phagocytophilum, is also spread by the Western Blacklegged Tick. Symptoms typically include fever, headache, chills, and muscle aches, usually appearing one to two weeks after a bite. Rocky Mountain Spotted Fever (RMSF), caused by Rickettsia rickettsii, is primarily transmitted by the American Dog Tick and Rocky Mountain Wood Tick. Initial symptoms can include fever, nausea, severe headache, and often a rash, though cases in Washington are rare.
Babesiosis, a parasitic infection caused by Babesia species, can lead to flu-like symptoms and hemolytic anemia. This disease is also linked to the Western Blacklegged Tick, with some cases reported in Washington. Tick-Borne Relapsing Fever (TBRF), caused by Borrelia bacteria, is characterized by recurring episodes of fever, headaches, and muscle and joint aches. Soft ticks transmit this disease, and the Western Blacklegged Tick can also be a vector. Other tick-borne illnesses include tularemia and tick paralysis.
Protecting Against and Responding to Tick Bites
To protect against tick bites, wear light-colored, long-sleeved shirts and long pants to make ticks easier to spot and prevent them from reaching skin. Tuck pant legs into socks or boots for an additional barrier. Use EPA-approved insect repellents containing DEET or picaridin on exposed skin and clothing.
Stay on marked trails, avoiding dense brush, tall grass, and leaf litter. After spending time outdoors, conduct a thorough tick check on yourself, children, and pets. Showering within two hours of being in tick habitats can help wash off unattached ticks. Maintaining your yard by keeping grass mowed, clearing leaf litter, and creating barriers between wooded areas and lawns can also reduce tick presence around your home.
If a tick is found attached, use fine-tipped tweezers to grasp it as close to the skin’s surface as possible. Pull upward with steady, even pressure without twisting or jerking, as this can cause mouthparts to break off. After removal, clean the bite area and your hands thoroughly with rubbing alcohol or soap and water. Avoid using “folklore remedies” like matches or petroleum jelly, as these can irritate the tick and potentially increase disease transmission. Seek medical attention if you develop symptoms such as a rash, fever, or flu-like illness within several weeks of a tick bite.