10 Symptoms of Lyme Disease in Dogs

10 Symptoms of Lyme Disease in Dogs


  1. Lameness: One of the hallmark symptoms of Lyme disease in dogs is recurrent lameness, which can shift from one leg to another. This lameness is often due to inflammation in the joints (Lyme arthritis) caused by the bacteria transmitted through tick bites.
  2. Lethargy: Dogs with Lyme disease may seem unusually tired or lacking in energy. They may not be as interested in playing or going for walks.
  3. Loss of Appetite: A decreased desire to eat or a sudden loss of appetite could be a sign of Lyme disease in dogs.
  4. Fever: An unexplained fever, which may come and go, can indicate an infection, including Lyme disease.
  5. Swollen Lymph Nodes: Enlarged lymph nodes, particularly those near the head, neck, and legs, might be present. These nodes might be tender to the touch.
  6. Joint Pain and Stiffness: Inflamed joints can lead to pain, making the dog hesitant to move or appear uncomfortable during physical activity.
  7. Depression: Changes in behavior, such as increased irritability or withdrawal, can be signs of Lyme disease in dogs.
  8. Difficulty Breathing: In rare cases, Lyme disease can lead to heart or respiratory issues, resulting in difficulty breathing.
  9. Kidney Problems: Lyme disease can affect the kidneys, leading to increased thirst and urination, vomiting, or diarrhea.
  10. Neurological Symptoms: In severe cases, dogs might exhibit neurological issues, including changes in gait, coordination problems, and even seizures.

Keep in mind that not all dogs will show all these symptoms, and some may exhibit only a few. If you suspect your dog may have Lyme disease, especially if you live in an area where it’s prevalent, it’s important to seek veterinary care for proper diagnosis and treatment. Preventative measures, such as tick control and regular tick checks, are crucial in areas where Lyme disease is a concern.

What exactly is Lyme disease?

Lyme disease arises from an infection with the spirochete bacterium called Borrelia burgdorferi. Dogs contract this disease when bitten by a tick that carries the infection. Once within the bloodstream, the Lyme disease bacterium spreads to various body regions, with a tendency to settle in joints or kidneys. The primary carrier of Lyme disease is the deer tick, often referred to as the black-legged tick. These ticks are prevalent across the midwestern and eastern regions of the United States, and they are also found throughout Canada, with Ontario having the highest concentration.

How does the transmission of Lyme disease occur?

Tick Bite: The transmission cycle begins when an uninfected tick larva or nymph feeds on an infected animal, typically a small mammal like a mouse or a deer. During feeding, the tick becomes infected with Borrelia burgdorferi if the host animal is carrying the bacterium.

Tick Life Stages: Ticks have several life stages: larva, nymph, and adult. Infected ticks can transmit the bacterium at any of these stages. Nymphs are especially concerning because they are small and harder to detect, and they are most active during the spring and summer months when humans and animals are more likely to be outdoors.

Host Bite: When an infected tick feeds on a new host, such as a human or an animal like a dog, it can transmit the Borrelia burgdorferi bacteria into the host’s bloodstream through its saliva.

Bacterial Spread: Once inside the host’s body, the bacteria can spread and cause infection. It often moves to the joints, causing inflammation and the characteristic symptoms of Lyme disease.

It’s crucial to understand that the Borrelia burgdorferi bacterium is not present in all ticks, and not every tick bite leads to Lyme disease. The likelihood of transmission varies due to factors such as the tick’s infection status, the duration of attachment to the host, and the implementation of suitable preventative measures.

Diagnosis and Testing

Lyme disease diagnosis typically involves a combination of clinical evaluation, laboratory tests, and consideration of the patient’s medical history and potential exposure to ticks. Here’s an overview of the diagnostic process:

Clinical evaluation

The veterinarian will start by conducting a thorough physical examination of the dog. They will assess the dog’s overall health, check for any signs of illness, and pay special attention to symptoms associated with Lyme disease, such as lameness, joint swelling, fever, and lethargy.

Medical history

The vet will inquire about the dog’s recent activities and any potential exposure to tick-infested areas. Information about recent outdoor activities, travel history, and known tick bites can help in assessing the risk of Lyme disease.

Blood tests

  • Enzyme-Linked Immunosorbent Assay (ELISA): This initial screening test detects antibodies produced by the dog’s immune system in response to the Lyme disease bacteria. However, false-positive results can occur, so confirmatory testing is required.
  • Western Blot Test: If the ELISA test is positive or inconclusive, a Western blot test is often performed. This test looks for specific antibodies against different components of the Lyme bacteria. A positive result on the Western blot is more indicative of Lyme disease.

Polymerase chain reaction (PCR) test

In some cases, PCR testing may be used to detect the presence of Borrelia burgdorferi DNA in the dog’s blood. This test is more useful in the early stages of infection.

Joint fluid analysis

If the dog is showing signs of joint inflammation, the veterinarian may perform joint fluid analysis to check for the presence of the Lyme bacteria.

It’s important to note that diagnosing Lyme disease can be challenging due to the variability of symptoms and the potential for false-positive and false-negative test results. Clinical signs, medical history, and laboratory results are all taken into consideration when making a diagnosis.

Treatment of Lyme disease in dogs

Lyme disease is typically treated with a course of antibiotics prescribed by a medical professional. The choice of antibiotics and duration of treatment can vary based on the stage of the disease and the severity of symptoms. Commonly used antibiotics for treating Lyme disease include doxycycline, amoxicillin, and cefuroxime. The treatment aims to eliminate the Borrelia burgdorferi bacteria from the body and alleviate symptoms.

It’s important to start treatment as early as possible, especially in the early stages of the disease, to prevent the development of more severe symptoms and complications. In some cases, individuals with advanced Lyme disease or certain complications may require longer or more intensive antibiotic regimens.

If you suspect you have Lyme disease or have been diagnosed with it, it’s crucial to follow your healthcare provider’s recommendations for treatment and to complete the full course of antibiotics as prescribed. Regular follow-up appointments and close communication with your healthcare provider are important to monitor your progress and ensure proper management of the disease.

Prevention of Lyme disease in dogs

Preventing Lyme disease in dogs involves a combination of measures to reduce the risk of tick bites and the transmission of the Borrelia burgdorferi bacterium. Here are some important steps you can take to prevent Lyme disease in your dog:

  • Tick Control Products: Use veterinarian-recommended tick prevention products for your dog. These may include topical spot-on treatments, oral medications, tick collars, or sprays. These products can help repel ticks and kill them before they can transmit the bacteria.
  • Regular Tick Checks: Perform thorough tick checks on your dog after outdoor activities, especially in tick-prone areas. Pay close attention to areas such as the ears, head, neck, underbelly, and paws. Remove any ticks promptly using fine-tipped tweezers.
  • Tick-Proof Yard: Maintain your yard by regularly mowing the grass, clearing leaf litter, and keeping shrubs trimmed. Consider creating a barrier between wooded areas and your yard using gravel or wood chips.
  • Avoid Tick-Infested Areas: When possible, avoid walking your dog in areas with high grasses, wooded areas, or places known to be infested with ticks.
  • Tick-Repellent Clothing: If you and your dog are venturing into tick-prone areas, consider dressing your dog in tick-repellent clothing or using pet-safe tick repellents. Discuss appropriate options with your veterinarian.
  • Vaccination: In some regions where Lyme disease is prevalent, there is a vaccine available for dogs. Consult your veterinarian to determine if vaccination is recommended based on your dog’s risk factors and location.
  • Regular Grooming: Regular grooming and bathing can help you spot and remove ticks from your dog’s fur before they have a chance to attach.
  • Environmental Management: If you live in a tick-endemic area, consider using environmentally safe methods to reduce tick populations in your yard, such as applying tick-controlling nematodes.
  • Consult Your Veterinarian: Regular veterinary check-ups are essential. Discuss Lyme disease prevention with your veterinarian, and make sure your dog is up-to-date on vaccinations and parasite control measures.


Being vigilant about the symptoms of Lyme disease in dogs can lead to early detection and effective treatment. By understanding the causes, symptoms, and preventive measures, you can ensure your canine companion enjoys a healthy and tick-free life. Remember, your proactive approach is a crucial step in safeguardin

Ryan Foley
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Dr. Ryan's journey in the field of veterinary medicine began with his graduation from the University of Adelaide in 2014. Armed with a solid educational foundation, he embarked on a career dedicated to the well-being and care of animals.