Lyme disease in dogs

Lyme disease is an infectious disease caused by Borrelia burgdorferi and is spread by ticks. Not only humans are at risk contracting Lyme disease. Dogs can contract Lyme disease and other tick borne diseases as well. Young dogs appear to be more susceptible to Lyme disease than older dogs. It is estimated that 5-10% of the dogs infected with Lyme disease develop symptoms.

When infection leads to disease in dogs the most common presentation is recurrent lameness due to inflammation of the joints which can be accompanied by a lack of appetite and depression. In more serious cases Lyme disease can damage the kidneys, heart or nervous system.

Symptoms of Lyme disease in dogs

In humans, Lyme disease is easily recognized. In most of the cases there is a red circular rash, called an erythema migrans, at the site of the tick bite. Dogs do not get such a typical skin rash and therefore the disease in dogs can be more difficult to recognize.

The symptoms in dogs can be difficult to recognize because lameness can be easily mistaken for an injury. If the lameness recurs and shifts around this is a sign that there is something else than an injury going on. The joints may be swollen, warm and painful.

The lameness comes on suddenly and can move around from one leg to another. This is different from lameness associated with arthritis, which comes on more slowly over a long period of time and affects the same joint consistently.

Some dogs develop kidney problems. Lyme disease can inflame and cause dysfunction of the blood filter in the kidneys. Kidney failure may set in and can be accompanied by vomiting, diarrhea, lack of appetite, weight loss, increased urination and thirst and abnormal fluid buildup.

  • Lameness
  • Swelling of the joints
  • Sensitivity to touch
  • Difficulty breathing
  • Fever
  • Lack of appetite
  • Lethargy/depression
  • Swollen lymph nodes

Diagnosis of Lyme disease in dogs

The veterinarian will ask for a thorough history of your dog’s health and its activities. If he suspects your dog has Lyme disease he will recommend testing your dog for Lyme disease and a number of other common tick borne infections such as ehrlichiosis, anaplasmosis, Rocky Mountain spotted fever (RMSF) and babesiosis.

He can also recommend other tests:

  • To evaluate organ function (kidneys, liver, pancreas)
  • Complete blood count (to assess for blood related conditions)
  • Electrolyte tests (to ensure your dog isn’t suffering from dehydration)
  • Urine tests (to look at kidney function)
  • Thyroid test (to see if the thyroid is producing enough thyroid hormone)
  • ECG (to screen for abnormal heart rhythm)

A veterinarian can use these blood tests to confirm Lyme disease. The test used most often is called an antibody test. It detects antibodies created by the dog’s immune system as a response to exposure to Lyme disease. This test can be false negative:

  • when the dog has been recently infected and antibodies are not yet developed
  • when the dog has a suppressed immune system causing a failure to develop antibodies
  • when the dog has been infected for a long time there may no longer be sufficient antibodies present

A positive test is therefor meaningful but a negative test is not.

Treatment of dogs with Lyme disease

If you dog has symptoms and gets diagnosed with Lyme disease the veterinarian prescribes antibiotics. When a dog tests positive for Lyme disease but is otherwise appearing healthy it may be unnecessary to treat it with antibiotics. However, Labradors and Golden Retrievers are predisposed to developing serious complications from Lyme disease. Any dogs of these two breeds that test positive for Lyme disease should be treated with antibiotics immediately.

When your dog shows clinical signs of Lyme disease such as fever, lethargy, in appetence and stiffness in joints the veterinarian will prescribe antibiotics. The antibiotic of choice is usually doxycycline but depending on your dog’s clinical signs and circumstances the veterinarian can choose another antibiotic. The recommended length of treatment is 4 weeks but has to be longer in some individual cases.

Antibiotic treatment does not always completely eliminate the Lyme bacteria. Symptoms may resolve but can reappear later and development of kidney disease in the future is always a worry. In those cases re-treatment is recommended.

Prevention of Lyme disease in dogs

Check for ticks

If possible avoid your dog from roaming in tick invested environments. Check your dog’s coat and skin daily and remove ticks properly to prevent the transmission of tick borne infections. It is more difficult to check for ticks on dogs than humans. Some dogs have thick coats and ticks can hide deep in the fur.

Start at the head and run your hands over your dog’s body. Check under the collar and use your fingers like the teeth of a comb. Check behind the ears, the toes, under the tail, and around the anus. Ticks are drawn to dark, hidden areas on the body. Check the skin for areas that appear red or irritated and watch for signs of excessive scratching or licking in particular areas. This can be a sign the tick has attached itself in this spot.

Remove ticks

When you find a tick be sure to get it out completely. You may wear a pair of disposable gloves when handling ticks. Using tweezers or special tick removal tools is advisable but make sure you grab the tick behind the head as close to the skin as possible to avoid accidentally causing the tick to vomit its content (including the bacteria it carries) into the blood stream of your dog.

Insect repellents

Your veterinarian can recommend a variety of sprays, collars and topical products to kill and repel ticks. Use the products under supervision of your veterinarian and according to the label’s directions.


There is a Lyme vaccine for dogs available. Talk with your veterinarian to see if a vaccination is right for your dog. Vaccinations can be administered at twelve weeks of age; require two shots, three weeks apart and yearly boosters.