Ticks and Lyme Disease: Symptoms, Treatment, and Prevention

A blacklegged tick on the stem of a plant.
CDC / James Gathany; William Nicholson

Tick-borne diseases, such as Lyme disease, are on the rise in people and dogs.

Reported cases in people in the U.S. increased from about 12,000 annually in 1995 to approximately 35,000 in 2019, according to the Centers for Disease Control and Prevention. However, not all diagnosed cases are reported and the CDC believes the true number of human infections is likely closer to 476,000 per year.

The U.S. Food and Drug Administration regulates products that are used to help prevent, diagnose, and treat this complex disease.

Who Gets Lyme Disease, What Time of Year?

Lyme disease is a bacterial infection most commonly transmitted via the bite of infected ticks, which attach to any part of the body.

The CDC recommends you check your dog daily, especially after they spend time outdoors. Pay particular attention to the collar area and around the eyelids, ears, tail, under the front legs, and between the back legs and toes.

On people, you will most often find ticks in moist or hairy areas such as the groin, armpits, scalp, and other hard-to-see areas of the body. And while everyone is susceptible to tick bites, campers, hikers, and people who work in gardens and other woody, and brushy areas with high grass and leaf litter, are at the greatest risk of tick bites. As many a suburban gardener can attest, with the expansion of the suburbs and a push to conserve wooded areas, deer populations are thriving. Deer are important sources of blood for ticks and are important to tick survival and movement to new areas, increasing the contact between people and ticks that carry the bacteria. Read more about the lifecycle of the bacteria and how it is transmitted to people and dogs.

In most cases, a tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted. If you remove it within 24 hours, the risk is greatly reduced. Symptoms of Lyme disease may take 3-30 days or longer to appear.

In the majority of cases, tick bites are reported in the summer months when ticks are most active and people spend more time outdoors. But this can extend into the warmer months of early autumn, or even late winter if temperatures are unusually high. Similarly, a mild winter can allow ticks and other insects to thrive and emerge earlier than usual.

Lyme Disease in People


What can I do to prevent Lyme disease?

  • Avoid wooded, brushy, and grassy areas, especially during warmer months (April – September), although tick exposure can occur anytime.
  • Wear light-colored clothing so that you can see ticks that get on you.
  • Treat clothing and gear with products containing 0.5% permethrin.
  • Apply insect repellents on uncovered skin, and ensure the products are registered by the Environmental Protection Agency.
  • Wear long pants and long-sleeved shirts, and shoes that cover the entire foot.
  • Tuck pant legs into socks or shoes, and tuck shirts into pants.
  • Wear a hat for extra protection.
  • Walk in the center of trails to avoid brush and grass.
  • Remove your clothing after being outdoors, and wash and dry them at high temperatures.
  • Do a careful body check for ticks after outdoor activities.

There are no licensed vaccines available in the U.S. to aid in the prevention of Lyme disease in people.

Symptoms and Stages

Symptoms of early-stage Lyme disease include:

  • muscle and joint aches
  • headache
  • fever
  • chills
  • fatigue
  • swollen lymph nodes

Another common symptom of Lyme disease is a rash (referred to as “Erythema migrans”). As many as 80% of infected people may develop a rash, however the characteristic “bull’s-eye” rash appears only 20% of the time.

Later-stage symptoms may not appear until weeks or months after a tick bite. They include:

  • irregular heartbeat and/or heart palpitations
  • arthritis (usually seen as pain and swelling in large joints, especially the knee)
  • nervous system abnormalities

When left untreated, the bacterial infection can spread to joints, the heart, and the nervous system and cause permanent damage. Lyme disease is rarely fatal.

However, if not treated properly, Lyme disease can become a chronic illness where symptoms might continue for weeks, months, or even years after the initial tick bite.

Lyme Disease in Dogs

Dogs can get Lyme disease, too. Typical symptoms in dogs include swollen joints and lameness, fever, and loss of appetite. Experts in the FDA’s Center for Veterinary Medicine say dogs with Lyme disease occasionally develop serious kidney disease that can be fatal.

There are ways you can reduce your dog’s risk for tick bites and Lyme disease, which also reduces the risk of infection for you.

  • Regularly check your dog for ticks.
  • Avoid allowing your dog to roam in tick-infested areas.
  • Treat your dog year-round with topical, oral and/or collar tick products. Talk to your veterinarian about which product is best for your dog.

Lyme disease occurs much less frequently in cats than in dogs, and cats’ susceptibility to the disease continues to be the subject of research. However, the same precautions for dogs apply to cats, especially if your cat goes outside, because ticks on cats can be transferred to people and ticks carry other diseases besides Lyme disease that are harmful to cats.

There are several FDA-approved products that treat and control tick infestations. A couple of tick products are also approved in dogs to specifically prevent infections with the bacteria that causes Lyme disease by killing the ticks that carry the bacteria.

Lyme disease vaccines are available for dogs, but not for cats. Talk to your veterinarian to see if vaccination is appropriate for your dog.

Lyme Disease Tests and Treatment

If you think you or your dog may have Lyme disease, contact your physician or veterinarian right away.

Your doctor or veterinarian may test for Lyme disease, and/or they may immediately begin antibiotic treatment, depending on the symptoms you or your dog exhibit.

Most blood tests check for the antibodies produced by the body to fight Lyme disease. CDC experts report it may take several weeks after a tick bite for initial antibodies to develop. Because of this, the blood tests may not be accurate if done soon after a tick bite.

For this reason, your doctor or veterinarian may recommend treatment with antibiotics before the diagnostic tests are complete. According to the CDC and other experts, people treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely.

In dogs, the more subtle early stages of Lyme disease often go unnoticed. Even if your dog appears healthy, your veterinarian may recommend yearly screening for Lyme disease, especially if you live in an area where Lyme disease is common. If your dog’s blood test is positive, your veterinarian may recommend additional testing, such as a urinalysis.

Written by the FDA.