Lyme Disease in Dogs

Lyme disease, caused by the bacteria Borrelia burgdorferi, is transmitted through the bite of a tick. It affects domestic animals (dogs, horses, possibly cats) and humans. Most Lyme disease transmissions occur due to the bite of the deer tick, also known as the blacklegged tick. Ticks themselves do not cause Lyme disease; however, they do carry and transmit the bacteria that does. Once a tick attaches, it takes one to two days for it to transmit the bacteria that causes Lyme disease, so the prompt removal of ticks is important for disease prevention.

In Canada, blacklegged ticks are most often found in southern British Columbia, southeastern and south-central Manitoba, southern, eastern and northwestern Ontario, southern Quebec, southern New Brunswick and Grand Manan Island and parts of Nova Scotia. Blacklegged ticks are spreading elsewhere in Canada. Established populations of blacklegged ticks have not been identified in Saskatchewan; however, infected ticks may be dropped off by migrating birds. This would explain the occasional cases of Lyme disease found in dogs that have not travelled outside of Saskatchewan.

Many animals can be infected with Lyme disease and show no clinical signs. Infection in apparently healthy dogs may be detected during routine screening. When clinical signs are present in dogs, fever, loss of appetite, painful or swollen joints, lameness that comes and goes, swollen lymph nodes and lethargy may be seen. If Lyme disease is left untreated, it can lead to damage in the kidneys, nervous system and heart.

Antibiotics are used to treat Lyme disease in dogs. Rapid improvement is usually seen in limb and joint disease; however, some dogs do not recover completely. Infection in animals may persist in spite of antibiotics and may require a second round of treatment. Additional treatments to help affected organ systems may be needed when the disease affects the kidneys, heart or nerves. Some animals may experience permanent joint damage from the infection.

The following table is a list of confirmed cases of canine Lyme disease occurring in Saskatchewan, from April 2014 to November 2020.

For more information on Lyme disease, visit the Ministry of Health’s page on Lyme disease.