Heartworm Disease Q&A

Heartworm Disease Questions and Answers

Summary: Dr. Ma explains all you need to know about Heartworm Disease. She answers pet owners' most common questions to help you avoid your pet getting this deadly disease.

Why is heartworm prevention important in Toronto?

Southern Ontario is located in an area where the warmer summer months help mosquitoes thrive. If a mosquito is infected with heartworm, it can then transmit this deadly parasite to pets via a simple mosquito bite. Once a dog has heartworm, it can be deadly, and very difficult to treat. That's why heartworm prevention is so important. It is also important to note that dogs with low heartworm burdens may show few or no symptoms at the beginning, which makes yearly heartworm testing equally vital.

If your dog is diagnosed with heartworm disease, they would need to restrict exercising for several months, which can prove difficult if your dog loves being active. Even before the actual heartworm treatment can begin, your dog's condition may need to be stabilized with appropriate therapy. In severe cases of heartworm disease, or when a dog has another serious condition, this can take several months. Once your dog is stable and ready for heartworm treatment, the recommended protocol has several steps, ranging over 1 year's time. Even after all treatment is completed, success is not guaranteed and depends on the severity of the disease. This is why, once again, prevention is so important - by keeping your pet on heartworm prevention you can avoid months and months of expensive and complicated treatment.

How is heartworm disease diagnosed?

Symptoms may differ between pets based on a number of variables. The longer the infection persists, the more likely you'll start noticing symptoms. Active dogs, dogs with heavy heartworm burdens, or those with other health issues often show very visible signs. Common signs in both cats and dogs include mild persistent cough, tiredness and fatigue after moderate activity, or complete reluctance to exercise, along with appetite and weight loss. The most common way to diagnose Heartworm is via antigen and antibody testing using a blood sample.

What is the best prevention medication for heartworm?

Heartworm preventives are only available by veterinary prescription. Owners should always talk to their vet first about what products are recommended, as vets can help tailor the optimal product based on your pet's medical history and travel history. Heartworm preventives come in different forms, including a monthly chewable pill, and a topical, “spot-on”, medication. A simple online search will offer many common and popular prevention brands out there like Advantage Multi, Revolution, and HeartGard. Make sure you are getting a product with efficacy against heartworm, and not just against fleas or ticks. So, remember, the first step is to talk to your trusted veterinarian! Secondly, ensure that you are administering the preventives to your pet on time, and keep a regular heartworm testing schedule. Just as you get a regular checkup with your doctor, your pets need a regular vet checkup as well, including a yearly heartworm test for dogs.

How do you administer heartworm medication?

Because heartworm preventive medication comes in different forms, there are also different ways to administer it. Pills are a popular option and come in a chewable or tablet form. However, this may not be a viable option if your pet has food allergies or is a picky eater. Another very effective option is a topical spot-on. Most heartworm preventives are given on a monthly basis during the months of June to November if you are residing in and around Ontario. Those travelling to the southern US over the winter may need to continue heartworm prevention year-round. Many heartworm medications include a calendar on their packaging so you can keep track every month. And don't forget to add a reminder each month on your smartphone too!

- Dr. Elva Ma

This article provides a summary view of some aspects you need to know about heartworm disease. We recommend you take the time to talk in detail with one of our licensed veterinarians. She/he will provide the best suggestions and strategies for your pet. For an appointment please contact us at (416) 966-1830 or click the button below.