Lyme disease is one of the best-known tick-borne illnesses in the United States, and it affects dogs as well as people. Whether it is a major concern for your dog depends a lot on where you live and where you travel. This overview covers the basics so you can have an informed conversation with your veterinarian.
What causes Lyme disease
Lyme disease is caused by bacteria called Borrelia burgdorferi. In North America, the bacteria are spread mainly by blacklegged ticks, sometimes called deer ticks. A tick picks up the bacteria by feeding on an infected animal, often a small mammal such as a mouse, and can later pass it on while feeding on a dog or a person. Transmission generally requires the tick to be attached for a period of time, which is one reason daily tick checks after outdoor time are so often recommended.
Blacklegged ticks are more common in some parts of the country than others. The Northeast, the mid-Atlantic and the upper Midwest are well-known areas for Lyme disease, but tick ranges can change over time. Your veterinarian will know the local picture.
Signs to watch for
Many dogs exposed to the Lyme bacteria never show signs of illness. When dogs do become sick, signs may appear weeks or months after the tick bite, and they can include:
- Lameness, sometimes shifting from one leg to another
- Swollen or painful joints
- Fever
- Lethargy or reluctance to move
- Decreased appetite
Less commonly, Lyme disease is associated with kidney problems in dogs, which can be serious. Signs like increased thirst, increased urination, vomiting or weight loss always deserve a call to your vet, whatever the cause.
These signs are not specific to Lyme disease. Joint pain and fever can have many causes, so do not try to diagnose your dog at home. Your veterinarian can examine your dog and decide which tests make sense.
Testing, treatment and prevention
Veterinarians have blood tests that can show whether a dog has been exposed to the Lyme bacteria, and some clinics include tick-borne disease screening in routine annual testing. A positive screening test does not always mean a dog is sick, so your vet will interpret results alongside your dog’s history and exam. If treatment is needed, your veterinarian will decide on the right plan.
Prevention usually combines several approaches. Talk to your vet about tick control products appropriate for your dog, and ask whether a Lyme vaccine is recommended where you live. Vaccination is not right for every dog, so it is a decision to make together with your veterinarian.
Everyday habits that help
Whatever prevention plan you and your vet choose, a few habits reduce exposure:
- Check your dog for ticks after walks in wooded, brushy or tall-grass areas. Pay attention to the ears, neck, armpits, between the toes and around the tail.
- If you find an attached tick, remove it promptly using fine-tipped tweezers or a tick removal tool, grasping close to the skin and pulling steadily. Ask your vet to show you if you are unsure.
- Keep grass mowed and clear leaf litter and brush around your yard.
- Stay toward the center of trails when hiking.
Remember that the ticks that bite dogs can bite people too. The CDC has helpful information on Lyme disease in people at cdc.gov/lyme.
