People who travel to the southern United States, or who have lived in BC, Manitoba, or Ontario are probably very familiar with heartworm.  While the disease is not endemic here in Alberta, incidence is on the rise.  This is primarily due to infected dogs moving to Alberta or travelling here.

The Heartworm Life Cycle

Heartworm is exactly what it sounds like – worms that live in the heart.  It is transmitted through a bite from an infected mosquito, and can be dangerous to your pet’s health.

Symptoms of heartworm in a dog can include:

• Mild, persistent cough
• Reluctance to move or exercise
• Fatigue after only moderate exercise
• Reduced appetite
• Weight loss

We recommend that all dogs be protected against heartworm with a monthly medication from May to October of each year.  If you travel outside the province with your dog, please let us know where you’re going, as you may need heartworm prevention for an extended period of time, depending on the climate you’re travelling to.

Heartworms in the Pulmonary Artery

Heartworms in the heart

 There are two easy ways to administer the prevention medications – one is a tablet, and the other is a topical liquid that is absorbed through your dog’s skin.

Depending on your dog’s travel history, it may be necessary to test for heartworm before giving the preventative medication, as some medications will kill any adult worms that are present, causing damage to your dog’s lungs, and possible death of your pet.  It is easy to test for heartworm – a quick in-house blood test is all that is involved, with results usually reported to you the same day.

If the test comes back positive, there is a treatment available.  Treatment must be carefully managed, often requiring hospitalization for one to two months in order to minimize harmful complications.

You may have noticed no mention of heartworm in cats.  Cats are unique creatures in that they are very resistant hosts.  In the rare case that a cat becomes successfully infected, the time between infection and death is usually very short.  Also the symptoms in cats are rather vague and can be easily confused for other disease processes.  If your cat travels to heartworm endemic areas or you are otherwise concerned about heartworm, please contact your veterinarian.

If you have any questions about heartworm disease or preventative medications, please ask your veterinarian.

Permission to use images provided by the American Heartworm Society (www.heartwormsociety.org).