Posted on Leave a comment

Which Ticks Carry Lyme and Other Diseases?

Ticks are a common concern for people and pets across the United States, but not all ticks pose the same risks. With hundreds of species in North America, many feed exclusively on wildlife or thrive in very specific habitats, meaning most are rarely encountered by humans. However, some species are widespread and commonly come into contact with people and pets in everyday outdoor spaces.

The ticks that most commonly affect humans include deer ticks, American dog ticks, lone star ticks, brown dog ticks, and Western blacklegged ticks. While these ticks share similar life cycles and environmental preferences, each carries its own set of potential pathogens and is found in distinct regions of the country.

For each tick species, you can see full details—including feeding habits, physical characteristics, and U.S. distribution maps—by clicking the “Learn More” button next to its section.


Deer Tick (Blacklegged Tick) – Ixodes scapularis

Deer ticks can be found in every U.S. state except Hawaii, but they’re most common along the eastern U.S. coast from Florida to Maine and in the Great Lakes region.

Nymphs and adult females pose the greatest risk to humans, with nymphs causing more Lyme cases due to their small size.

Diseases carried:

  • Lyme disease
  • babesiosis
  • bartonellosis
  • anaplasmosis
  • B. miyamotoi

Western Blacklegged Tick (Ixodes pacificus)

Western blacklegged ticks are found along the U.S. west coast, most commonly in coastal California, Oregon, and Washington.

Juvenile western blacklegged ticks feed on birds, small rodents, and even lizards, while adults prefer deer and other large mammals such as humans.

Diseases carried:

  • Lyme disease
  • anaplasmosis

Lone Star Tick (Amblyomma americanum)

Once mostly confined to the southern U.S., lone star ticks have been spreading north and now inhabit much of the eastern United States—from Texas and Iowa to the Atlantic coast—even reaching as far north as Maine. They remain most common in southern regions.

Lone star ticks are considered one of the most aggressive tick species

Diseases carried:

  • Ehrlichiosis
  • Tularemia
  • Southern Tick-Associated Rash Illness (STARI, caused by Borrelia lonstari)
  • Alpha-Gal Syndrome (meat allergy)

Brown Dog Tick (Rhipicephalus sanguineus)

Brown dog ticks are found throughout the entire United States, though they are most common in warmer southern regions.

These ticks pose a significant disease risk to dogs, carrying bacteria that can cause illnesses such as canine ehrlichiosis and babesiosis.

Diseases carried:

  • Rocky Mountain spotted fever
  • Ehrlichiosis (possible)
  • Canine ehrlichiosis (Ehrlichia canis)
  • Canine babesiosis (Babesia canis)

American Dog Tick (Dermacentor variabilis)

American dog ticks are found throughout areas east of the Rocky Mountains and along a small section of the west coast. They typically inhabit woods, brush, and tall grasses.

Larvae and nymphs feed on small mammals such as rodents, while adults prefer larger mammals.

Diseases carried:

  • Rocky Mountain spotted fever (RMSF)
  • Tularemia

Protect Yourself by Knowing the Risks

Remaining informed about ticks and the diseases they carry is key to keeping yourself, your family, and your pets safe during tick season. Know which ticks are active in your region and understand the potential risks. Staying vigilant and prepared is the best way to enjoy the outdoors safely.

Don’t forget—TickCheck can help you identify any tick! If you’ve been bitten and aren’t sure what species it is, simply upload a high-quality, detailed photo and request a free tick identification. We’ll be able to tell you what you’re looking at. We’ll let you know exactly what you’re looking at. Once you receive your results, you can either research the potential risks yourself or call our customer service team at 1-866-713-TICK to get our opinion. We’re always happy to help!


Worried About a Recent Tick Bite?

If you’ve removed a tick and want peace of mind, TickCheck offers fast and reliable tick testing services. Simply send the tick to our lab, and we’ll identify the species and test it for Lyme disease and other common pathogens. Knowing whether a tick was carrying disease can help you and your doctor make informed decisions about next steps.

Posted on Leave a comment

Lyme Disease and Wildlife: How Ticks Spread Through Nature

white footed mice spread lyme disease

Lyme disease is the most common tick-borne illness in the United States, and awareness of it has grown steadily over the past few decades. Most people now recognize Lyme as a serious concern, but fewer realize just how quickly it is spreading. Once primarily found in the Northeast, Lyme cases are now being reported across much of the Midwest, mid-Atlantic, and is even spreading into parts of the southern and western United States. As the disease spreads, staying informed and prepared becomes more important than ever.

But how exactly does Lyme disease move from wildlife into people? Ticks don’t start out infected. Instead, they acquire the bacteria that causes Lyme disease—Borrelia burgdorferi—by feeding on an infected animal host, such as a mouse. Once acquired by the tick, the bacteria can be transmitted to humans or pets during a later bite, turning a simple tick encounter into a potential health risk.


Which Ticks Spread Lyme Disease?

Blacklegged tick / deer tick size comparison

Not every tick’s bite can spread Lyme disease. In the United States, only the blacklegged tick (also called the deer tick) is able to pass on Lyme. Other tick species can still make you sick, but with different illnesses—such as Rocky Mountain spotted fever or ehrlichiosis.

Recent analysis of the results of TickCheck’s tick testing concludes that of 2,000+ specimens, 30% of blacklegged ticks tested carried the Lyme bacteria. It’s important to remember, however, that not every bite by an infected tick will result in transmission of Lyme to the host. These ticks must typically be attached for 18-24 hours before transmission can occur.

Blacklegged ticks can be hard to spot. Unfed ticks are small, flat, and dark in color. As they feed, they swell in size, becoming rounder and more swollen. An engorged tick may also lighten in color.


Wildlife and the Spread of Lyme Disease

Ticks feed on more than 300 different animals- everything from deer and cattle to chipmunks and even birds. Of these animals however, only some are capable of carrying and transmitting Lyme to a feeding tick: mice, chipmunks, birds and shrews.

Juvenile ticks feeding from white-footed mice are especially likely to become infected, making these small mammals key players in Lyme’s spread. Once a tick acquires the bacteria, it can transmit it during future feedings.

Deer, while not sources of Lyme bacteria themselves, play a different role. They are the preferred host for adult blacklegged ticks (hence the nickname ‘deer tick’), and by carrying them into forests, fields, and even backyards, they help expand where ticks can be found.


Protecting Yourself and Your Family

If you live in an area where deer, mice, or other wildlife are common, there’s a good chance ticks are present as well. Prevention is the best protection- here are a few simple steps you can take:

  • Be cautious in tick-prone areas: tall grass, brush, wooded trails, and edges where lawns meet the woods.
  • Check yourself, your kids, and your pets after spending time outdoors.
  • Act quickly if you find a tick. Remember, it usually takes 18–24 hours for Lyme transmission to occur, so removing a tick promptly and properly is the best defense.
  • Use safe removal tools. Carrying a dedicated tick remover ensures you can take ticks off quickly and completely.

By understanding the role wildlife plays in Lyme disease and practicing prevention, you can reduce your risk and stay safer outdoors.


Worried About a Recent Tick Bite?

If you’ve removed a tick and want peace of mind, TickCheck offers fast and reliable tick testing services. Simply send the tick to our lab, and we’ll identify the species and test it for Lyme disease and other common pathogens. Knowing whether a tick was carrying disease can help you and your doctor make informed decisions about next steps.