Don't let their small size and inconspicuous nature fool you: Ticks can give you and your pets harmful infectious diseases, including Lyme disease. Ticks that carry disease appear to be growing in number and covering a wider geographical area as the climate changes.
Ticks of concern in the United States include deer, brown dog, American dog, lone star, Rocky Mountain wood, Gulf Coast, and western black-legged ticks. In addition to Lyme disease, ticks can spread infections, including Rocky Mountain spotted fever, tularemia (also called rabbit fever), anaplasmosis, babesiosis, ehrlichiosis, and the red meat allergy known as alpha-gal syndrome.
The best way to reduce your risk of such infections is to prevent tick bites. When going outdoors, experts recommend these practices:
- Use tick repellent containing DEET or other ingredients registered with the Environmental Protection Agency.
- Treat clothes and gear with products containing 0.5 percent permethrin.
- Wear long-sleeved shirts and long pants, and choose light-colored clothing so you can spot ticks right away.
- If you’re walking on a trail, stay in the center so you’re not touching plants or the tips of branches where ticks hide.
- Once you get home from an area you know or suspect has ticks, carefully inspect your whole body and check your pets for ticks or tick bites.
If you’ve been bitten by a tick and it’s embedded in your skin, it’s important to remove it as quickly as possible to help reduce your risk of getting a tick-borne disease. The best way to remove it is with clean, fine-tipped tweezers. Get the tweezers as close as possible to your skin, then pull the tick steadily upward to remove its body (including its mouthparts). Be careful not to twist the tick, or the embedded mouthparts may break off in your skin. Wash the bite and your hands well. Dispose of the tick by sealing it in a container or flushing it down the toilet; do not crush it.
Do not attempt to remove a tick using heat, petroleum jelly, or other folk remedies, as this can actually cause the tick to become agitated and release infected fluid into your body.
Call your doctor if you develop a rash, a fever or chills, or a headache days or weeks after removing a tick. Even if you didn’t see a tick, if you develop these symptoms after you’ve been in an area that could have ticks then you should check in with your healthcare provider.
Deer Ticks Can Spread Multiple Infections
Also called black-legged ticks, deer ticks are common in woods and grassy areas across the eastern United States. Reddish-brown adults are only 1/8 of an inch long. Immature ticks about the size of a poppy seed can also bite.
Lyme Disease
Deer ticks infected with the bacteria Borrelia burgdorferi can cause Lyme disease in people, dogs, and cats. Lyme disease is found in certain parts of the United States, typically the Northeast, mid-Atlantic, and upper Midwest.
You might not notice the tick or its bite. But if you do, removing the tick within 48 hours can help limit your chances of contracting Lyme. The first symptom is often a bull’s-eye rash. The rash may appear within one to two weeks, but not everyone gets or notices the rash, in part because it doesn’t itch or may not be obvious in people with darker skin tones. Other signs include flu-like symptoms such as fever, chills, headaches, aches, and swollen lymph nodes.
If you have any of these symptoms and you’ve removed a tick, or if you have spent time in an area with ticks and known Lyme disease and you think you may have been bitten, see your doctor for diagnosis and treatment, as Lyme disease can often be cured. If untreated, long-term infection can cause headaches, stiffness, arthritis, and an irregular heartbeat.
Anaplasmosis, Ehrlichiosis, Babesiosis, and Powassan Virus
Black-legged ticks can transmit the bacteria that causes anaplasmosis and ehrlichiosis. Early signs of infection include fever, headache, muscle aches, and nausea or vomiting. Babesiosis and the Powassan virus can also result from a black-legged tick bite.
Babesia, the parasite that causes babesiosis, invades red blood cells and destroys them. Babesiosis is relatively rare compared with Lyme disease, but doctors are diagnosing it more often than in years past as awareness of the disease increases and climate change drives up case counts.
Cases of babesiosis are typically concentrated on the East Coast, but it has also been reported in certain states in the Midwest and West. Babesiosis can be mild, and many people don’t experience symptoms. When symptoms do occur, they can be flu-like and include a low-grade fever, fatigue, and body aches. The disease can be dangerous for immunocompromised people, older adults, and individuals who do not have a spleen, an organ that filters blood. In some cases, black-legged ticks can infect people with babesiosis and Lyme at the same time.
Like babesiosis, Powassan virus disease can have mild symptoms or cause none at all. As of August 2026, the virus was most commonly reported in the Northeast, with a few cases reported by residents of Wisconsin and Minnesota.
Symptoms include fever, headache, vomiting, and weakness. In rare cases of severe disease, the virus can infect the brain, causing encephalitis. There is no medication for treatment, but the disease usually goes away on its own with rest and over-the-counter pain relievers.
Brown Dog Ticks and Pet Disease
This type of dog tick is found nearly everywhere in the United States. It likes dogs of every variety but rarely bites people. Adult brown dog ticks are about the size and color of the deer tick. The bites of brown dog ticks can be extremely dangerous to your pet: They can spread bacterial infections, including canine ehrlichiosis, bartonellosis, and babesiosis. Symptoms of a tick-borne disease in your dog may include fever, depression, weight loss, and lameness. Talk to your vet about the warning signs of tick-borne infections.
Brown dog ticks can live in indoor and outdoor environments, meaning they can be active year-round. The tick can live in your home or in places that dogs gather, like a kennel or dog park. If your dog has been outside in a kennel, in the backyard, or in a place that multiple dogs gather, check them often and thoroughly for ticks. Brown dog ticks hide, so make sure to look under rugs, behind draperies, under radiators, and in cracks if you think you have an infestation. The best way to get rid of them is to hire an exterminator.
Start by parting your dog’s fur around the tick. Remove a tick from a dog in the same way you would a person: Use fine-tipped tweezers; grab the tick as close to the dog’s skin as you can; and slowly pull out the tick, making sure not to twist it. Be sure to dispose of the tick, and wash the bite and your hands well.
American Dog Ticks and Rocky Mountain Spotted Fever
Also called the wood tick, the American dog tick feeds on people, dogs, and other animals that carry infectious disease. This tick seeks out different hosts as it grows: mice and other rodents in its early stages, and people and pets in its adulthood. The full-grown ticks are reddish brown and about a half-inch long. The American dog tick’s geographical range extends east of the Rocky Mountains and along parts of the Pacific coast.
American dog tick bites can spread Rocky Mountain spotted fever, caused by the bacteria Rickettsia rickettsii, in both people and pets. These ticks also spread the bacterial disease tularemia, also called rabbit fever, and can cause tick paralysis (loss of muscle function, which is thought to be caused by tick saliva). If you’re bitten, you may see discoloration around the bite.
Rocky Mountain spotted fever cases occur throughout the United States, and symptoms include fever, headache, body aches, swelling around the eyes or the backs of the hands, and nausea and vomiting that come on within 3 to 12 days of the bite. Two or three days after the fever begins, look for a spotty rash that starts on your ankles and wrists and spreads (though 10 percent of patients never develop a rash). Rocky Mountain spotted fever can be fatal if treatment is delayed, but timely treatment with the antibiotic doxycycline is usually effective. Be sure to see your doctor early if you have been exposed to ticks and have any of these symptoms.
Lone Star Ticks Can Carry Several Diseases
Found from central Texas and the wooded areas of the Midwest to the coast of Maine, lone star ticks are brown or tan, and about 1/3 of an inch long. Females have a distinctive white spot on their backs — which is where the name comes from — while males have scattered spots or lines outlining their bodies. They can bite at any stage of their three-year life cycle.
Ehrlichiosis and Tularemia
Lone star ticks can spread ehrlichiosis and tularemia. Tularemia symptoms include skin rash or ulcers, a high fever, and swollen lymph nodes. The infection can be treated with antibiotics, but if left untreated, it can be fatal.
Southern Tick-Associated Rash Illness
Lone star tick bites can cause southern tick-associated rash illness (STARI), which shares some Lyme disease symptoms. Signs of STARI include a bull’s-eye rash at the bite site, which often appears within a few days of the bite and can expand to 3 inches across. Though STARI symptoms include body aches, fever, and fatigue just as Lyme disease does, STARI doesn’t carry the long-term effects of Lyme. STARI typically occurs in the southern United States, where Lyme disease usually does not.
Heartland Virus
Lone star ticks have transmitted the rare Heartland virus, first identified in 2009 in two men in Missouri. As of July 2026, more than 80 cases have been reported from states in the midwestern, northeastern, and southern United States. Infection causes fever, headaches, and low platelet and white blood cell counts. There is no treatment.
Alpha-Gal Syndrome
Potentially life-threatening allergic reactions to consuming red meat have been reported in some people bitten by lone star ticks, a phenomenon known as alpha-gal syndrome (AGS). The Centers for Disease Control and Prevention calls alpha-gal syndrome an emerging health threat, noting that between 2017 and 2022 more than 90,000 suspected cases were documented in the United States. While the lone star tick is commonly associated with alpha-gal syndrome, other ticks have not been ruled out.
Alpha-gal is a sugar molecule found in red meat and dairy. Someone with alpha-gal syndrome may not have an allergic reaction every time they consume red meat, and they may only be allergic to certain red meats.
Allergic reactions include hives, rash, nausea, shortness of breath, and swollen lips, tongue, eyelids, and throat. Most healthcare providers recommend that people with alpha-gal syndrome avoid red meat and, in some cases, dairy and gelatin.
Rocky Mountain Wood Ticks and Colorado Tick Fever
The mocha-colored Rocky Mountain wood tick lives in the northwestern United States and in Canada. Young Rocky Mountain wood ticks bite small rodents; adult ticks are more likely to latch on to deer, dogs, livestock, and people.
The Rocky Mountain wood tick's bite can transmit diseases, including a virus that causes Colorado tick fever, as well as Rocky Mountain spotted fever, tick paralysis, and tularemia. Colorado tick fever symptoms resemble the flu, leaving you tired, achy, and with chills. The illness is usually short-lived, but there is no treatment.
Gulf Coast Ticks and Spotted Fever
The pecan-colored Gulf Coast tick lives along the coast in the southern and mid-Atlantic United States and as far inland as Oklahoma and Texas. The Gulf Coast tick can transmit the bacteria Rickettsia parkeri, which can cause a spotted fever that's a milder type of Rocky Mountain spotted fever. Signs of this infection may appear anywhere from 2 to 10 days after the bite. The bite itself might look like a pimple and could be followed by a headache, an overall rash, and fever. Treatment to clear up the infection with antibiotics is usually effective.
Western Black-Legged Ticks and Anaplasmosis
This black and brown tick lives in the western United States and British Columbia. As a young tick, it prefers small rodents and lizards. As an adult, the western black-legged tick affects humans, pets, deer, and other large mammals. It's also a carrier of a number of diseases, including Lyme disease, babesiosis, and anaplasmosis.
Anaplasmosis, caused by the bacteria Anaplasma phagocytophilum, can result in flu-like symptoms such as fever, chills, headache, and muscle aches. It may be particularly severe and even life-threatening when antibiotic treatment is delayed or if the patient is immunocompromised.
Additional reporting by Jean Brannum.
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