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Symptoms guideLyme disease symptoms in dogs
Most exposed dogs never get sick. Here are the signs vets look for when they do, including the rare kidney form and what a red circle on the belly usually means.
Quick answer
Most dogs exposed to Lyme bacteria never show signs. When signs do appear, the most common are lameness that shifts from leg to leg, fever, tiredness, loss of appetite, swollen joints and swollen lymph nodes. They often show up weeks to months after the tick bite. Rarely, Lyme is linked to serious kidney disease.
- CAPC says most dogs exposed to Borrelia burgdorferi appear to develop infections without signs.
- The most common signs in dogs that do get sick are fever, inflamed joints (polyarthritis), swollen lymph nodes and loss of appetite.
- The Merck Veterinary Manual describes lameness that comes and goes and shifts between legs, sometimes with swollen, painful joints.
- A rare kidney disease (Lyme nephropathy) has been linked to Lyme in dogs, though Merck notes the cause-and-effect link is not fully proven.
Most exposed dogs show no signs
This surprises many owners. A dog can test positive for Lyme exposure and seem completely healthy. Cornell University’s diagnostic lab cites an older estimate that only about 5 to 10% of dogs that test positive show signs, while noting the true share may be higher today because vets and owners are more aware of the disease.
A positive test with no signs is a conversation to have with your vet, not an emergency. Read how vets handle this in our dog treatment guide.
First signs of Lyme disease in dogs
Signs usually do not appear right after the tick bite. According to Cornell, lameness often starts 2 to 5 months after infection. Many owners first notice their dog limping, being slow to get up, or not wanting to play or walk.
| Sign | What you might notice |
|---|---|
| Shifting lameness | Limping that comes and goes, or moves from one leg to another |
| Swollen, painful joints | Stiffness, reluctance to climb stairs or jump, sensitivity when a leg is touched |
| Fever | Your dog feels warm, is quiet or seems “off” |
| Lethargy | Low energy, more sleeping, less interest in walks |
| Loss of appetite | Eating less or skipping meals |
| Swollen lymph nodes | Firm lumps under the jaw, in front of the shoulders or behind the knees |
These signs are not specific to Lyme. Joint problems, injuries and other tick-borne infections such as anaplasmosis and ehrlichiosis can look similar, and dogs can have more than one infection at once. Only a vet can sort out the cause.
Vet sources describe a better outcome for these acute joint signs: dogs generally improve once antibiotics start. In some dogs, CAPC notes that joint inflammation can become long-lasting and may continue despite treatment.
Lyme nephritis: the rare kidney form
In a small number of dogs, Lyme disease has been linked to a serious kidney disease, often called Lyme nephritis or Lyme nephropathy. The kidneys start leaking protein, and the problem can progress to kidney failure. The Merck Veterinary Manual calls this form “extremely low” in incidence, but it is the most serious complication.
Vet sources list signs such as:
- Swelling of the legs (fluid buildup)
- A swollen belly from fluid
- High blood pressure and, in some cases, sudden blindness
- Blood clots
Because protein in the urine can show up before obvious illness, CAPC recommends blood and urine tests for dogs that test positive for Lyme exposure. Ask your vet whether a urine protein check makes sense for your dog.
Call your vet if your dog is limping, has swollen joints, a fever, or is tired and not eating. Get prompt vet care if your dog has swelling in the legs or belly, sudden vision problems, or seems seriously unwell. These signs need attention whether or not Lyme is the cause.
Is there a bullseye rash in dogs?
In people, an expanding red rash is one of the best-known early signs of Lyme disease (see our Lyme rash guide). Dogs are different. The veterinary sources we reviewed, including CAPC and the Merck Veterinary Manual, list joint, fever, lymph node and kidney signs for dogs. They do not list a bullseye rash among the typical signs. Fur also makes skin changes hard to see.
What about a bright red circle on a dog’s belly? Owners often notice these because belly skin has less fur. A red ring or spot there can have many possible causes, and most are not Lyme disease. A rash alone is not a reliable way to tell whether a dog has Lyme. If you see a red circle on your dog’s skin, especially one that spreads, is itchy, scaly or sore, or appears where you removed a tick, have your vet take a look. If you found a tick, mention when and where you removed it.
How signs compare with Lyme in people
People with Lyme disease often notice a rash and flu-like symptoms within days to weeks. Dogs more often show nothing at all, or show joint signs months later. If your dog had a tick, it is also worth checking yourself and your family. See Lyme disease symptoms in people and what to do after a tick bite.
Frequently asked questions
What are the first signs of Lyme disease in dogs?
The first sign many owners notice is lameness that comes and goes or shifts between legs. Fever, low energy, loss of appetite and swollen joints or lymph nodes are also common. Many exposed dogs show no signs at all.
How long after a tick bite do dogs show signs of Lyme disease?
Signs are often delayed. Cornell notes that lameness often appears 2 to 5 months after infection, so a dog may seem fine for weeks after the bite.
Can Lyme disease symptoms in dogs come and go?
Yes. Vet sources describe lameness that is intermittent and can move from one leg to another.
Can Lyme disease affect a dog’s kidneys?
Rarely. Lyme has been linked to a serious protein-losing kidney disease in a small number of dogs. Vets may check urine for protein in dogs that test positive.
Is a red circle on my dog’s belly Lyme disease?
Usually not. A bullseye rash is not a typical sign of Lyme in dogs, and red rings on the skin have many possible causes. Have your vet check any new, spreading or sore patch.