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Pets guideLyme disease in dogs: a guide for owners
How dogs get Lyme disease, how common it is, the signs to watch for, and how vets test, treat and help prevent it.
Quick answer
Yes, dogs can get Lyme disease. It spreads through the bite of an infected blacklegged (deer) tick. Most exposed dogs never get sick. Those that do may have a fever, low energy and lameness that moves from leg to leg. Vets can test for it, antibiotics usually help quickly, and tick control is the best prevention.
Veterinary guidance from the Companion Animal Parasite Council (CAPC) and the Merck Veterinary Manual agrees on a few key points:
- Lyme disease in dogs is caused by Borrelia burgdorferi bacteria, carried by blacklegged ticks.
- Most dogs that are exposed develop an infection without any signs of illness.
- Dogs that do get sick are treated with antibiotics, and doxycycline is the usual first choice.
- Year-round tick control is recommended. Vaccination is a choice you make with your vet, based on where you live and your dog’s tick exposure.
How do dogs get Lyme disease?
Dogs get Lyme disease the same way people do: from the bite of an infected tick. In North America, the main carriers are the blacklegged tick (often called the deer tick) in the Northeast and Midwest, and the western blacklegged tick on the Pacific coast.
Ticks pick up the bacteria by feeding on infected wild animals, especially rodents. According to the Merck Veterinary Manual, a tick usually has to stay attached for at least 24 hours before it can pass the bacteria on, and most transmission happens 36 to 48 hours into feeding. That is why finding and removing ticks quickly matters. Learn more in our guide on how long a tick needs to be attached.
A few things that do not spread Lyme disease to dogs:
- Other dogs. Vet sources say it is not thought to spread through bite wounds or body fluids.
- Insects. Lyme is not known to spread through insects such as fleas or mosquitoes.
- The American dog tick. Despite its name, the CDC says this tick cannot transmit Lyme disease bacteria (it can spread other diseases). See which ticks carry Lyme disease.
How common is Lyme disease in dogs?
It depends a lot on where you live. CAPC reports that Lyme disease in dogs is most common in the Northeast, the upper Midwest and West Coast states. In areas where it is established, the share of dogs that test positive for exposure ranges from about 1.4% in the West to 13.3% in the Northeast.
In the southern U.S., infection in pets is rarely documented unless the dog has traveled to a higher-risk area. In some tick surveys, more than half of the nymph and adult blacklegged ticks tested carried the Lyme bacteria.
Dogs also act as an early warning for people. CAPC notes CDC research finding that counties where more than 5% of dogs tested positive tended to see human Lyme cases emerge, while counties under 1% had little to no risk. You can look up results reported for your area on the CAPC parasite prevalence maps, and see human risk on our Lyme risk map.
Signs of Lyme disease in dogs
Most exposed dogs never show signs. Cornell University’s diagnostic lab cites an older estimate that only about 5 to 10% of dogs that test positive become ill, while noting the real number today may be higher. When signs do appear, lameness often shows up 2 to 5 months after infection.
Common signs include:
- Lameness that comes and goes or shifts from one leg to another
- Fever
- Low energy and loss of appetite
- Swollen, painful joints
- Swollen lymph nodes
Rarely, a serious kidney problem sometimes called Lyme nephritis can develop. Unlike in people, the classic bullseye rash is not one of the typical signs vets look for in dogs. Our full guide covers Lyme disease symptoms in dogs in detail.
See your vet if your dog is limping, has swollen joints, seems feverish or tired, or stops eating, especially after time in tick areas. Go sooner rather than later if your dog has swelling in the legs or belly or seems very unwell, since vet sources link these signs to the rare kidney form.
How vets diagnose Lyme disease in dogs
There is no single test that proves a sick dog has Lyme disease. Vets put together several clues: possible tick exposure, the dog’s signs, lab results, how the dog responds to treatment, and ruling out other causes. Other tick-borne infections, such as Anaplasma and Ehrlichia, can cause similar signs and sometimes occur at the same time.
| Test | What it tells your vet |
|---|---|
| Screening antibody test (often C6-based, can be done in the clinic) | Whether the dog has been exposed to Lyme bacteria. CAPC says a C6-based test is often the preferred first screen. The C6 marker comes from natural infection, so vaccination does not cause a positive result. |
| Quantitative C6 test | A measured antibody level, sometimes checked before and after treatment. Levels do not always drop, so vets judge success mainly by how the dog is doing. |
| Lyme multiplex test (Cornell) | Separates antibodies from vaccination (OspA), early infection (OspC) and longer-term infection (OspF). |
| Urine and blood work | Checks for protein in the urine and other signs of kidney involvement, which matters for planning care. |
A positive screening test means exposure, not necessarily illness. Many healthy dogs in high-risk areas test positive. CAPC advises against giving antibiotics to a positive dog with no signs or lab abnormalities, but recommends checking for other infections, running blood and urine tests, and starting tick control.
Treatment and outlook
Dogs with signs of Lyme disease are treated with antibiotics. Vet sources name doxycycline as the usual first choice, typically for about a month, with amoxicillin as an alternative for some dogs, such as growing puppies. Many dogs improve within one to three days, though signs do not fully clear in every dog. The kidney form needs more intensive care. Read more about Lyme disease treatment in dogs.
Vaccines and prevention
CAPC recommends year-round tick control with a product labeled to work against blacklegged ticks, daily tick checks, and prompt tick removal. Lyme vaccines for dogs exist, and your vet will weigh your region and your dog’s lifestyle before recommending one. A vaccine does not replace tick control.
Who it is for, how long it lasts and what it can’t do.
Tick preventives, tick checks and yard tips.
Can my dog give me Lyme disease?
No. The CDC says there is no evidence that dogs or cats spread Lyme disease directly to their owners. But dogs can carry ticks into your home and yard, where a tick may later bite a person. Checking your dog daily after outdoor time helps protect the whole family. See our guides on what to do after a tick bite and preventing Lyme disease in people.
We are collecting real experiences about Lyme disease in their dogs from people who have lived it, shared with their permission. As stories come in, they will appear here, clearly marked as personal experience rather than medical advice.
Cats and horses
Dogs are not the only animals ticks bite. Cats in high-risk areas often test positive, but illness is rarely described. Horses can develop Lyme disease too, and it can be hard to diagnose. Read about Lyme disease in cats and Lyme disease in horses.
Frequently asked questions
Can dogs get Lyme disease?
Yes. Dogs can be infected through the bite of an infected blacklegged (deer) tick or western blacklegged tick. Most exposed dogs never show signs, but some develop fever, lameness and other symptoms that need a vet.
How do dogs get Lyme disease?
From the bite of an infected blacklegged tick that stays attached long enough to pass on the bacteria, usually at least 24 hours and most often 36 to 48 hours. Vet sources say it is not thought to spread from dog to dog.
What does Lyme disease do to dogs?
In dogs that get sick, it most often causes joint inflammation, with lameness that shifts between legs, plus fever, tiredness and swollen lymph nodes. Rarely, it is linked to a serious kidney disease.
Do dogs get Lyme disease from other dogs?
No. Vet sources say Lyme disease is not thought to spread through bite wounds or body fluids. It comes from tick bites.
Can my dog give me Lyme disease?
The CDC says there is no evidence that pets spread Lyme directly to people. However, dogs can bring infected ticks into your home or yard.