Western Black-Legged Tick: Everything You Need To Know
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Western black-legged ticks are one of the biggest nuisances pet parents can face, despite how small they are. They can be difficult to spot, and they can spread several illnesses to you and your pets.
Whether you’ve spotted a black-legged tick, or you just want to be prepared in case you do, here’s everything you need to know.
Key Takeaways
- The Western black-legged tick (Ixodes pacificus) is a small, reddish-brown tick that’s one of the main vectors of Lyme disease and anaplasmosis in the western United States.
- Western black-legged ticks are found primarily along the Pacific Coast of the United States, most commonly in California.
- The best way to prevent Western black-legged tick bites is to avoid areas where they thrive, such as wooded or bushy areas.
What Is a Western Black-Legged Tick?
The Western black-legged tick (Ixodes pacificus) is a small, reddish-brown tick that’s considered one of the main vectors of Lyme disease and anaplasmosis in the western United States.
It takes about two to three years for it to reach maturity, and it goes through four stages along the way: egg, larva, nymph, and adult.
The larvae emerge in early summer and are active from July to September, according to Linda Giampa, executive director of the Bay Area Lyme Foundation, a leading sponsor of Lyme disease research in the U.S.
“Barely the size of a printed period at the end of a sentence, the larvae generally remain in the leaf litter waiting to attach to nearly any accessible mammal, reptile, or bird,” she says.
The nymphal stage comes next, and this is when most people and pets are infected. Because ticks are so small during this stage, they’re harder to detect. Nymphs are active from the May to August following the larval stage and are commonly found in moist leaf litter and in or around wooded areas.
Nymphs typically attach to smaller mammals such as mice, voles, squirrels, and chipmunks, but will readily attach and feed on:
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Humans
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Birds
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Lizards
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Cats
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Dogs
Once fed, they also drop off and molt, emerging as adults in the fall, according to Giampa.
Adult Western black-legged ticks are most active from October to May.
Where Is the Western Black-Legged Tick Found?
Western black-legged ticks are found primarily along the Pacific Coast of the United States, most commonly in California.
In fact, these tiny parasites have been found in all but two of the 58 counties in California, where tick season is year-round due to the state’s mild climate, according to Giampa.
They’re also found in Oregon, Washington, and some parts of Arizona, Nevada, and Utah.
They thrive in humid environments like forests, grasslands, and coastal scrubs. And they’ve even been found in the beach areas in California, according to a study funded by Bay Area Lyme Foundation.
What Diseases Can the Western Black-Legged Tick Spread?
While Lyme disease is a big concern, unfortunately, it isn’t the only health issue related to the Western black-legged tick. These little buggers are a known carrier of several diseases, and can transmit them to humans, dogs, cats, and horses.
Some of the most common diseases spread by Western black-legged ticks are:
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Lyme disease: A bacterial infection caused by bacteria called Borrelia burgdorferi
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Anaplasmosis: A bacterial infection caused by the bacteria Anaplasma phagocytophilum
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Hard tick relapsing fever: A bacterial disease cause by Borrelia miyamotoi
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Babesiosis: A rare parasitic infection that’s caused by the parasite Babesia microti and affects red blood cells
Dogs are particularly vulnerable to Lyme disease and other tick-borne pathogens, while cats aren’t as susceptible to some.
“Interestingly, cats appear to be very resistant to the development of Lyme disease even if infected with the bacteria that causes it. However, they can develop other tick-borne diseases including babesiosis,” says Giampa.
While each disease is caused by a different type of microbe, ticks may carry multiple bacteria, viruses, and parasites.
“These separate infections, contracted with the same tick bite, may cause symptoms to vary from person to person, cause challenges with diagnosis and impact which treatments are effective in eradicating infections,” says Giampa.
Are Western Black-Legged Tick Diseases Treatable?
That said, many tick-borne diseases are treatable if diagnosed early.
If caught early, most cases of Lyme disease can be resolved with antibiotics, such as doxycycline and amoxicillin.
However, it’s commonly misdiagnosed due to lack of awareness and unreliable diagnostic tests, despite being the most common vector-borne infectious disease in the country, according to Giampa.
If not treated promptly, Lyme disease can progress and become difficult to treat.
People with late-stage Lyme disease may deal with chronic symptoms that can include:
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Joint pain and neck stiffness
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Headaches
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Memory problems
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Hearing and vision changes
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Dizziness
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Shortness of breath
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Rashes
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Chronic inflammation of the brain and spinal cord
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Nerve pain
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Numbness or tingling in the hands or feet
Babesiosis, which is caused by a parasite, typically requires a combination of antimicrobial therapies.
To improve prognosis, preventive measures and early detection are crucial for ensuring effective treatment and minimizing complications.
How To Prevent Western Black-Legged Tick Bites
The best way to prevent Western black-legged tick bites is to avoid areas where they thrive. This means staying out of wooded or bushy areas with tall grass and leaf debris.
Giampa also recommends:
- Keeping grass mowed
- Removing leaf litter and debris as much as possible
- Creating barriers with wood chips or gravel between wooded areas and recreational spaces
You also want to make sure your pets are properly protected from fleas and ticks. Samuel Varon, DVM, practicing veterinarian and owner of Broadway Veterinary Hospital in Sacramento, California, says veterinary-recommended topical or oral tick preventives are highly effective. Some of the most highly rated are:
When choosing a tick preventive, make sure you’re getting a brand that’s appropriate for your specific pet, in a dosage that makes sense for their size.
It’s best to talk to your vet before giving your pet a flea and tick preventive.
Dr. Varon says you might also want to consider a Lyme disease vaccine for dogs.
In the case that you or your pets do encounter ticks, you also want to be prepared to respond effectively and quickly.
First, familiarize yourself with the proper way to remove a tick, which is to position tweezers between the skin and tick’s mouth and tug gently, according to Giampa, who adds that if you yank too hard, the tick’s mouth can stay behind along with the Borrelia burgdorferi bacteria that can cause Lyme disease.
Dr. Varon also recommends saving the tick in a sealed bag to show your vet. It may help with a diagnosis if your pet gets sick.
Make sure you’re always diligently checking yourself and any pets that go outside too.
Of course, you’ll want to remove any ticks that latch onto your pets, but you also want to check for crawling creatures that might be trying to hitch a ride into your home.
Western Black-Legged Tick FAQs
What is the size of a Western black-legged tick?
Western black-legged ticks are tiny, which can unfortunately make them hard to spot. Adult ticks are the size of a sesame seed, while nymphs are about the size of a poppyseed.
What does a Western black-legged tick look like on a dog?
At first, a Western black-legged tick looks like a small, reddish-brown or brownish-black spot on your dog.
On dogs, they’re often found in or near the ears, around the neck, under the collar, and between the toes, according to Dr. Varon.
If the tick has been there a while and becomes engorged, it can grow to the size of a pea or larger and is usually a pale gray color.
