Lyme disease: protecting your dog


Transmitted by infected tick bites (not by other dogs or humans), Lyme Disease is very serious for dogs.

It has many outcomes, including infection of your dog’s tissues, joint inflammation, kidney and nervous system damage, and possibly heart disease. The most common symptom for dogs is joint inflammation, causing recurrent lameness.

Other symptoms to watch out for are:

  • Arthritis
  • Lameness
  • Pain and fever
  • Decreased appetite
  • Dehydration
  • Decreased activity
  • Swollen lymph nodes and joints

Lyme Disease can be deadly for dogs, so if you think your dog may have contracted it, bring them to the veterinarian right away.

Certain dogs are at greater risk than others, based on how often they go outside (particularly in areas with tall grass or brush), whether they are exposed to areas with deer (who carry ticks), their overall health, their vaccination history, and most importantly, where you live. Certain areas have a greater incidence of ticks and Lyme disease infections.


Here’s a map from the Canadian informational website, Canine Lyme Disease, which highlights the areas of highest risk in Canada. Note that southern Ontario, particularly the GTA, is at a high level of risk.

Living in the red “endemic” zone means that around 75% of unvaccinated dogs will test positive for Lyme Disease at some point in their lifetime.

Preventive care is the best way to protect your dog. Tick control treatments should be administered throughout the year, except during the winter if the temperature stays below 4°C. If you live in a red endemic area, you should also have your dog vaccinated against Lyme Disease.

Ultimately, the best thing to do is to talk to your veterinarian about the right way to prevent Lyme Disease and tick infestations in your pup. Your vet will discuss the specifics of medication and prevention with you and recommend a treatment that is right for your specific dog.

Another great resource to learn about dogs, ticks, and Lyme Disease is