HEARTWORM- What Your Vet May Not Be Telling You In Ontario

Feb 07, 2023 Dan


The pest season is quickly approaching, which means that we are starting to get notifications from our vets recommending heartworm preventatives. The pressure to put our pets on heartworm preventatives will be kicking into high gear. The pictures in the vet offices, social media and even traditional media will begin highlighting the insecticides that should be used to prevent your pet from getting this terrible parasite. I have a few thoughts on this, but here are a few things that I need you to know.

#1. Most of what you will read here is my opinion. I have raised dogs for over 35 years and have a very focused approach on what to feed, how to vet and what does and does not go into my fur friend’s body.

#2. This is not a blog to bash veterinarians. I have all the respect in the world for DVM’s and as a pet parent I truly believe they can be an important part of the team that helps keep my dogs healthy and the best chance for a long life with me.

#3. I respect every individual’s decision when it comes to how they choose to raise their pets. I just hope that they have all of the accurate information needed to make a good and informed decision.

#4. This specific blog is relevant to pet parents who live in Ontario. If you live in Florida and many of the other states in the Southeast U.S., not applicable.

OK, so here it is. The chance of your dog contracting heartworm in Ontario is really low. It is too cold. The environment is not suitable for transmission and development of heartworm larvae. Assessing your pet’s risk of getting heartworm is really important because the preventative that is being used is a chemical insecticide. Putting these chemicals in you pets body has both short- and long-term side effects that can damage your pet’s health.

Most people don’t realize that a preventative does not stop your pet from being infected. The chemical poisons the heartworm larvae at the microfilaria stage of development, causing them to die inside the body.

In my view, the traditional veterinary community is well-intentioned in their recommendations about heartworm prevention recommendations. However, why do almost all vet offices use the heartworm “visit” email or phone call when there is such a small chance of your pet getting heartworm??? It does not compute. In my opinion, I would never put a chemical poison in my pet’s body to “prevent” something that has very little chance of taking place. Period.

This is what I do.

1. I will test my pet for heartworm every year in very early spring. This will do two things. If by chance my dog did get heartworm, it is treatable since the larva have not had the time to become adults and settle in the heart. As well, it just gives me peace of mind that all is OK.

2. I always have a natural spray that I use when I go hiking or in an area at a time when mosquitos are prevalent. See Natural Spray Options.

3. I use an all-natural powder that helps keep the bugs away. You can learn more about it here.

4. I focus on keeping my pet’s immune function robust. I feed an appropriate diet that is balanced for a carnivore. I avoid feeding highly processed foods and treats. I also ensure that the gut is strong and healthy by supplementing with a good pre- and probiotic. I also believe strongly in a good liver cleanse once a year.

I think the heartworm scare in Ontario is overblown. The risk of heartworm in Ontario does not warrant the potential side effects of putting an insecticide in my pet’s body. It can be difficult to say no to your vet. Remember, your vet needs to work with you and respect your beliefs and your decisions you make about your pet.

And, as always, The Proof Is In The Poop!


Another good read with further information Ticks, Fleas and Heartworm 2022 Blog