Lyme Disease in Dogs

Causes, Treatment, and Prevention

lyme disease in dogs

Lyme disease is the most common tick-borne disease in the United States. Dogs that contract Lyme disease can develop arthritis, kidney disease, nervous system disorders, and heart issues. Symptoms don't always present but include fever, swelling, and lameness when they do. Dogs that spend a lot of time outdoors in tick-ridden environments are at a heightened risk for contracting Lyme disease, and swift diagnosis and treatment are essential to preventing long-term complications. Fortunately, there are preventative measures you can take to protect your dog from Lyme disease.

What Is Lyme Disease?

Lyme disease is an infection of the bacterium Borrelia burgdorferi, spread through tick bites. The bacteria enter the dog's body while the tick is feeding and then migrate through the tissue, usually localizing in the joints, causing acute arthritis. If the dog is not treated, the bacteria may cause damage to the kidneys, nervous system, and heart.

Lyme disease has been reported in every state in the United States and many other parts of the world. In the U.S., it is most common in the Northeast, Midwest, and West Coast regions. However, not all ticks carry Lyme disease. The black-legged tick (also known as the deer tick) and the western black-legged tick are the primary transmitters of Lyme disease in the U.S.

Symptoms of Lyme Disease in Dogs

Unlike humans with Lyme disease, only about 5 to 10 percent of dogs infected with B. burgdorferi will develop symptoms. Symptoms may show up within two to five months after infection or much later. Lyme disease symptoms are wide-ranging and nonspecific. If your dog seems ill and has been exposed to a tick-ridden environment, visit your vet to discuss a possible Lyme disease diagnosis. If your dog was around ticks but does not seem ill, it is still advised to see a vet. Here is a list of early symptoms of Lyme disease in dogs.


  • Fever
  • Decreased appetite, lethargy, and weight loss
  • Swollen and painful joints or lymph nodes
  • Lameness in one or more limbs


If your dog has Lyme, the bacterial infection can result in a fever. You can potentially detect a fever in your dog if it is shivering but its ears, paws, and stomach have a warm touch. 

Decreased Appetite, Lethargy, and Weight Loss

A lack of appetite and general lethargy may signal the beginning of kidney issues with your dog. Lyme disease may potentially affect your dog's kidneys so if you notice your dog has begun to lose weight from not eating, call your vet immediately.

Swollen and Painful Joints or Lymph Nodes

A dog with Lyme may feel a generalized stiffness due to swollen and painful joints and lymph nodes. Swollen or painful joints may feel a bit warm to the touch. Check your dog's lymph nodes for swelling. They are located in the neck, chest, behind the knees, armpits, and groin areas.


Swollen and painful joints may lead to lameness in one or more limbs. The lameness may be intermittent and can shift to different limbs.

Causes of Lyme Disease

Lyme disease is caused by B. burgdorferi bacteria spread by tick bites, and environment and lifestyle can contribute to exposure.

  • Tick bites: A bite from an infected tick, likely the black-legged deer tick (Ixodes scapularis), is the only way a dog can contract Lyme disease since not all ticks carry the bacteria. A tick acquires the B. burgdorferi bacteria when feeding on infected mice or other small animals and then transmits it to dogs. It takes one to two days for an attached tick to transmit the bacteria to its host, making prompt tick removal essential to curbing Lyme disease.
  • Environment: Ticks are more prevalent in wooded, grassy areas, especially in the Northeast, Northwest, and upper Midwest. Ticks are most active when temperatures are above 45 degrees Fahrenheit and when the humidity is at least 85 percent.
  • Lifestyle: Dogs with very active, outdoor lifestyles are more likely to encounter ticks and possibly contract Lyme disease.

Diagnosing Lyme Disease in Dogs

A tick must be attached to your dog for 36 to 48 hours before an infection is transmitted. To prevent Lyme disease, early removal of the tick is essential. Vets use a combination of clinical signs, medical history, and diagnostic tests to diagnose Lyme disease in dogs. There is no single test for Lyme disease, but there are tests to detect B. burgdorferi antigens in the blood. The presence of antigens indicates that the dog was exposed to the bacteria, but it does not mean the dog has Lyme disease. Your vet will likely perform diagnostic tests to rule out other health problems and determine whether or not the bacteria has affected the kidneys or other organs and systems. This may include blood and urine analyses, X-rays, and the collection and analysis of joint fluid.


Dogs with Lyme disease are typically treated with antibiotics for several weeks, and most dogs experience a rapid improvement in symptoms soon after. Treatment may not completely eradicate the bacteria, but it can eliminate symptoms. Dogs with kidney disease will require a longer course of antibiotics and additional medications and treatment measures. Dogs with nervous system or heart problems may need to be referred to a veterinary specialist for advanced diagnostics and treatments.

Prognosis for Dogs With Lyme Disease

If your dog's Lyme disease is treated swiftly and successfully, the prognosis is good. However, the prognosis is more guarded if Lyme disease has gone undiagnosed and untreated, spreading to the kidneys, heart, or nervous system. Untreated Lyme disease can cause kidney failure, subsequent vomiting, and increased thirst and urination. Often, dogs that develop kidney failure face a terminal prognosis.

Even after all other symptoms are resolved, dogs with Lyme disease may still likely develop chronic arthritis in their lifetime. Dogs that have had Lyme disease could potentially become prone to developing chronic kidney disease.

How to Prevent Lyme Disease in Dogs

Tick control is the best way to prevent Lyme disease and other tick-borne diseases. Check your dog for ticks often and remove them immediately. This is especially important in peak tick season (spring and fall) and after your dog spends time in areas where ticks are known to thrive. Keep grass and brush trimmed in your yard, so ticks have fewer places to hide. Consider treating your yard for ticks if you live in an area where ticks are prevalent.

Young man taking care of a dog
Marc Oeder / Getty Images

Tick prevention products are highly effective, and many flea control products also contain ingredients to kill ticks. Ask your veterinarian about the best tick control options for your dog.

Removal of a dog tick
PK-Photos / Getty Images

Your vet may recommend a vaccination against Lyme disease if you live in an at-risk area. Many veterinary specialists do not recommend a routine vaccination because so few dogs develop Lyme disease symptoms and those that do tend to respond well to treatment. A vaccination won't offer total protection but it can help lower a dog's risk of contracting and carrying the disease. Still, it is not a substitute for tick prevention medications.

Dogs are generally vaccinated at around 12 weeks of age and are given a booster two to four weeks later. The vaccine is ideally administered before tick season each year.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.
Article Sources
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