Heartworm Testing Services for Pets

Heartworms are harmful parasites that once inside your pet, can cause irreversible lung and heart disease. Heartworm testing ensures we can detect and address an infection early on, which improves our ability to treat your pet. If your pet is due for their testing, please contact us at 416.941.8920.

How is my pet tested?

Typically, it takes at least 6 months after your pet has been infected for our test to be able to detect heartworms. We’ll do an antigen (protein) test, which can detect at least 1-3 female adult heartworms. We’ll send the test to our in-house laboratory, which means we can get the results back in a timely manner. The earlier we can detect heartworms, the better chance we have of treating heartworm disease and supporting your pet to make a full recovery. Adult dogs should get tested during their annual wellness exam, if they’re showing signs of heartworm disease or before they start a new preventive medication. Since it’s harder to detect heartworms in cats, we typically use an antigen and antibody test to detect any exposure to heartworm larvae.

How might heartworm disease affect my pet?

Heartworm disease is extremely harmful to your pet’s body, especially for their lungs and heart. It is serious and can be fatal. The longer heartworms live inside your pet, the more damage they can cause to other organs in their body. Even after the heartworms are eradicated, they can still leave long lasting damage to their heart, lungs, and arteries, which can negatively affect their quality of life. Since your dog’s body is more conducive to heartworms, they tend to live inside them for longer and even multiply. Though heartworms are less likely in cats, they can still cause severe damage to their respiratory system.

What are the signs?

Sometimes, pets are asymptomatic when they first contract heartworms, with symptoms progressing overtime. If you notice any of these signs in your pet, please contact us immediately:

  • Persistent cough
  • Loss of appetite
  • Tiredness
  • Weight loss
  • Vomiting

  • Last updated: June 20, 2022.

    1. WE CAN NOW SEE ALL CASES BY APPOINTMENT ONLY This includes vaccines, wellness exams, blood work, spays and neuters, dental services, and more!


  • Our doors are now open! All visitors can enter directly into the reception area.
  • We require a 24 hr cancellation notice for appointments during this time. A cancellation fee will be applied otherwise.
  • Continue the use of credit cards as the preferred payment method.
  • Curbside pickup of food and medication is still available (unless you have used our online store and are having your order delivered directly to your home).
  • Parking is available in our parking lot (behind the clinic) as well as on the street.

    Monday to Friday: 8:00 am - 6:00 pm
    Saturday: 8:00 am - 1:00 pm
    Sunday: Closed

    Thank you for your patience and understanding and we look forward to seeing you and your furry family members again!

    - Your dedicated team at Bay Cat & Dog Hospital