Toronto Veterinarians - Pet Wellness Network

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Contact Willowdale Animal Hospital

Open 24 Hours, Year Round

256 Sheppard Ave. West
Toronto, ON M2N 1N3
(416) 222-5409

The Toronto Veterinarians at The Pet Wellness Network will  treat your animals for heartworm prevention.Springtime (and heartworm!) has come to Toronto and the GTA!

Warmer days and evenings mean we can stay out longer and more comfortably in the great outdoors with our four-legged friends.

Unfortunately, warmer weather means the mosquitoes are out too, and it’s time to once again think about heartworm prevention for our dogs and cats.

When infected mosquitoes bite into your pet, they shoot a bunch of tiny baby worms called microfilariae into your pet’s blood stream. Once they’re inside, the dreaded worms plant themselves into the right side of the heart and waste no time in rapidly reproducing and blocking blood flow throughout the body of your pet, which can be fatal if not treated immediately. As the worms travel, they rupture blood cells and vessel walls along their way to the heart. They are simply reckless. Since there is no way to completely avoid mosquitoes, veterinarians recommend monthly treatments to help prevent the heartworm larvae from growing into adult form inside your pet’s heart and lungs.

Heartworm Infection – Signs to look out for:

  • Sluggishness in your pet
  • Excessive coughing (due to blockages in the heart and lungs)
  • Vomiting (it isn’t really vomit – it’s your pet coughing up the worms!)

While heartworm isn’t exactly contagious because one dog or cat can’t give it to another, a mosquito could bite an infected pet and then pass it onto the next animal they bite.  Humans can catch heartworms this way too! Except in humans, the symptoms are less severe – the worms don’t circulate to the heart, but the larvae can create cysts in human eyes and lungs.

There are 3 kinds of heartworm medication: topical, oral, and injectable. Ask your vet which type is best for your pet!


  • To make giving oral meds less of a struggle, give the tablet to your dog wrapped inside a treat.
  • When applying a topical medication, be sure not to bathe your pet within a week of application. A bath beforehand is best.
  • Be aware that some pets can be allergic to the medication itself, or to the flavouring agents used in them. Watch to ensure your pets behaviour doesn’t change after being administered the meds.

If you notice your pet exhibiting any of the symptoms of heartworm, you should take them into their vet’s for a check without delay, and ask them to perform a heartworm test on your dog or cat. Remember immediate treatment for heartworm is always best.

If you have further questions about heartworm, please do not hesitate to contact your local Toronto Pet Wellness Network animal hospital today.

Image courtesy of the Companion Animal Parasite Council.

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