Dundas Euclid Animal Hospital 416-362-9696

Lyme Disease

In our last blog, Dr. Barrientos discussed how the warmer weather means more creepy crawlers and the diseases they transmit. We have all heard about Lyme disease whether it be in the news, the media and some of us even know somebody who has Lyme disease. But what does this mean for our fur babies at home? Today’s blog hopes to shed some light on Lyme disease in pets.


As we learned from last month’s blog, ticks are the vectors that transmit Lyme disease to animals and humans. Lyme disease is not an infection caused by the tick itself but rather by the bacteria, Borrelia Burgdorferi. The deer tick picks up the bacteria by biting infected animals like deer and small rodents. The bacteria then lives in the gut of the tick and is transmitted through the saliva when the tick bites. Once the bacteria is in the body of the pet, it is up to the immune system to recognize it and wage a war to fight it off.


If your pet’s immune system loses the battle against the bacteria, there are a variety of signs they might exhibit:

  • Lethargy
  • Shifting lameness – recurrent lameness due to inflammation in joints
  • Stiffness/aches in joints
  • Fever
  • Swollen/enlarged lymph nodes

In more serious cases the bacteria can travel to the kidneys and cause damage. In this case you may see:

  • Weight Loss
  • Increased thirst and urination
  • Decreased appetite
  • Blood in the urine
  • Vomiting and/or diarrhea

The disease can present in a variety of ways and it may be difficult to determine the cause. Some of our aging pets may exhibit these signs, as what we think is the “normal aging process”. It is for this reason that it is important to keep up with annual tests.


Testing for Lyme disease in animals is actually quite simple and readily available. As a screening test we recommend running an annual parasite panel, known as the 4DX. This tests for heartworm as well as exposure to three tick borne diseases including Lyme disease. A positive on this test does not mean your dog has Lyme disease, but rather has been exposed to it. Exposure does not always equal disease, as a portion of dogs will fight off the infection. To determine whether your dog actually has the disease it requires a follow up test, known as the quantC6. This test measures how much of an immune response is occurring in the body. If the response is very high then the body is still trying to fight off the infection, however if it is low then we know that the dog was exposed but successfully fought off the infection.


Once we have confirmed your pet has Lyme disease it is important to start treatment immediately. Most uncomplicated cases of Lyme disease are treated on an outpatient basis with a four-week course of antibiotics (doxycycline). The rare case will require a longer course of treatment and/or hospitalization. Once the infection is clear it does not mean the animal is out of harm’s way, as infection does not confer lifelong immunity. This means your pet can be infected again if not properly protected. Fortunately, the treatment of most cases of Lyme disease in animals is seen with success. This may come as a surprise to some as this is not always the case in humans.


We know that both humans and animals can get Lyme disease, however a Lyme infected dog can NOT directly give you Lyme disease. Rather the ticks on your dog can jump onto you and then potentially transmit the disease. The risk factors are the same for animals and people: wooded areas, tall grass etc. If your dog is picking up ticks, chances are you are being exposed as well. By testing your pet you are gaining valuable information about your own risk of exposure.


At Dundas Euclid Animal Hospital we had 5 cases of confirmed Lyme disease last year, and have already had 2 confirmed cases this year. The threat in our neighborhood is rising and we need to be protecting our pets and ourselves. For our canine companions we have two options for protection:

1. Topical or oral parasite preventatives to prevent ticks from biting and transmitting the bacteria.
2. The Lyme vaccine for dogs in high-risk areas. In these areas it is possible for the occasional tick to break through the parasite preventative. If this occurs, the Lyme vaccine will have your dog prepared to fight off an infection.

We have not discussed much in regards to our feline counterparts, as they have historically shown somewhat of resilience to Lyme disease. However as the prevalence of ticks increase, so does the risk to cats. So stay tuned as the preventative products for cats are on their way!

Ultimately by protecting your furry friends, you will be protecting yourself and your loved ones. So I encourage you to drop by the clinic to discuss testing and these preventative options in more detail! Bring your critter with you and we will be sure they get lots of cuddles and treats.