Heartworm Season Is Here Again!

Heartworm disease is caused by worms that live in the heart and large blood vessels of the lungs.  Heartworm is a parasite that is spread through common mosquito bites and can cause significant damage to the heart and lungs.  Heartworm season begins in June and lasts until the beginning of November.  

How do I know if my dog has heartworm?
In general, most dogs will not show any signs of heartworm until the disease is quite advanced.  Some more common symptoms can include coughing, exercise intolerance, and fainting.  If left untreated heartworm can ultimately be fatal.

How can I prevent my dog from getting heartworm?Without a doubt, heartworm prevention is better than attempting to treat an existing infection.  There are a number of different products available that are meant to prevent heartworm infections, and one of our veterinarians can recommend the product that would best be suited to your dogs lifestyle.  The majority of preventive medications also offer the added protection of flea and intestinal worm protection.  In general, these medications are administered once monthly through the heartworm season and are extremely safe.  

Does my dog have to have a blood test done before starting heartworm medication?
Yes, before you giving any heartworm preventives we recommend a quick and simple blood test to ensure that your pet has not been infected with heartworm already.  Concerns about either missing a dose or not absorbing 100% of the given dose has lead the manufacturers of these medications to recommend a blood test beforehand.  Even for pets that have consistently been on heartworm prevention, we still advise a heartworm test in the spring (April or May).

Can my dog be cured if he has become infected with heartworm?There is a treatment available for animals that have already become infected with heartworm, however the medication can be very difficult on your dogs body.  Once diagnosed, the treatment for heartworm may still death.  This is why we strongly recommend prevention.

Can my cat get heartworm?
Yes.  Cats are susceptible to heartworm infection as well.  In general, the risk of your cat becoming infected with heartworm is much lower than dogs, especially if you keep your cat indoors.  We generally do not recommend heartworm prevention in cats in this region.

Heartworm Fast Facts:
1.  Approximately 250 dogs were diagnosed with heartworm last year, with almost 50 cases reported in the GTA.


2.  Heartworm can infect more than 30 different species including coyotes, foxes, wolves, wild cats, sea lions, and humans.

3.  It takes 6 months for a mature worm to develop in the heart.  This means that 6 months have to pass before we can detect a heartworm infection in your dog.

4.  In warmer climates, such as Florida and other southern states, mosquitos are more prevalent throughout the year.  As a result, your pet could become infected at any point during the year.  Please be sure to tell us if you travel (or will be travelling) to warmer climates with your pets.

For more information please visit the American Heartworm Society webpage.