Heartworm, or Dirofilaria Immitis, affects more and more pets in Québec. This parasite, which is responsible for heartworm disease, affects the most important organ in the body: the heart. Fortunately, you can detect this disease with a screening test and effectively protect your pet with a preventive treatment.

Is it a serious disease?

Heartworm disease is dangerous because the worms are located in a delicate part of your animal’s body. A large number of adult worms can prevent the heart from functioning normally. Since the vast majority of infected animals don’t show symptoms until advanced stages of the disease, treatment is more complex, challenging and expensive. In the worst cases, death is inevitable.

How can I protect my pet?

We recommend using a preventive treatment (tablets, injections or liquid vials) once a month from about June to November. If you’re travelling outside the country, please let your veterinarian know so they can assess the risk based on your destination.

We also recommend that you have your pet tested for heartworm by taking a blood sample at their annual checkup.

How can my pet contract heartworm?

Heartworms are spread as larvae through the bites of infected mosquitoes. As they become adult worms, they settle inside the heart, blood vessels and pulmonary arteries. Since we get a lot of mosquitoes, any pet that goes outside without protection can be infected. Wetlands and marshes at nightfall are particularly conducive to mosquito bites.

Are only dogs affected?

Although dogs are the most commonly affected species, cats can get heartworms too. However, cats will get fewer worms with a shorter lifespan, which help them resist infestations.