Looking for more information about Parvovirus? Click here!

At Guelph Lake Veterinary Hospital, we believe that it is extremely important to protect your outdoor pets from Heartworm and Lyme disease. These are 2 different mosquito and tick-borne diseases and while Heartworm is less common in southern Ontario due to preventative measures taken by pet owners, Lyme disease is quietly increasing in prevalence as more ticks move into the area.

Our "Heartworm" test at GLVH will check for both Heartworm and Lyme disease, as well as two other less common blood-borne diseases, at which time we can make a recommendation for treatment (if a positive test is received) or approve a preventative medication plan which can protect your pet for the duration of the outdoor season.

Why is testing important?

Unfortunately, both Heartworm and Lyme disease are silent infections. It is very difficult to know that your pet has been infected by a carrier mosquito or tick. Without testing, symptoms don't appear until the infection has set in and sometimes caused irreversible damage. Using a preventative medication on a pet that has already been infected can also be a deadly combination.

Testing is quick, easy and affordable. A simple blood test that offers a positive/negative result can allow us to quickly assess whether it is safe to use a preventative medication for this summer season or whether treatment should be started.

What is Heartworm, and how does it affect my pet?

Heartworm is a parasitic worm that infects host animals via the bite of a mosquito. The microscopic parasite travels via the mosquito's mouth parts and into the animal's bloodstream. Once in the bloodstream, it takes between 90-100 days for the larvae to evolve into young adult worms that are present in the animal's bloodstream and move to the heart and lungs. The presence of the worms causes changes to the way the animal's arteries and heart function, restricting blood flow and, if left untreated, eventually leading to congestive heart failure.

If recognized early enough (via regular testing), a pet can be treated and lung and heart function can be restored.

Symptoms of heartworm infection are generally only noticed once the infection has progressed enough to cause significant, and often irreversible, damage to the animal. Although treatment for heartworm is available, it is costly and can be dangerous to the pet. Severe cases can mean the pet is host to hundreds of adult worms, which means a difficult and lengthy treatment process.

While cases of heartworm disease are certainly not rampant in Ontario, mosquitoes remain a fact of life during the spring and summer months. In a 2010 study, it was shown that over 75% of Canada's reported heartworm cases were found in Ontario. It is, therefore, GLVH's recommendation that heartworm testing be performed at least every other year and that preventative medications be administered properly to reduce the opportunity for infection. Prevention truly is the best medicine in this case.

What is Lyme disease and how does it affect my pet?

Lyme infection is an increasingly common disease in Southern Ontario, and is transmitted via the blacklegged tick. Climate change has allowed these ticks to migrate north from the Eastern US states, where they have been common for years, and they are now being found more regularly in Ontario. There are certain hotspots near the Great Lakes that are known for their tick population, but ticks are increasingly being found across the province as they migrate on birds and other roaming animals.

The tick's life cycle begins on small mammals (mice, squirrels etc.) but they require blood from a host in order to reproduce. Most often they will attach themselves to white-tailed deer for their "feeding" time, but they sit on tall grasses or branches and wait for a host to walk by so that they can latch on. This means that humans and animals out walking in areas where ticks are found could certainly acquire a tick while exploring.

These ticks will latch on to the host and feed for about 36 hours - the bite is painless, and they will expand to several times their size over the course of the days that they are attached. Assuming that the tick is carrying the Lyme disease bacteria, it is transferred near the end of their feeding cycle, so if the tick is removed promptly after they've attached, the chance of infection is reduced significantly. There is a technique to removing the tick completely, and it is important not to crush the tick's body or the bacteria could still be transferred to either your or your pet. Ticks have very strong jaws and can be deeply embedded in your pet - call your veterinarian if you aren't sure how to remove it or if you've gotten all of it.

Recently, heartworm test manufacturers have added the ability to test for Lyme infection using the same sample taken for the heartworm test. This allows our veterinarians to check for both diseases with little to no increase in cost to our clients.