Heartworm Testing

Heartworms cause heartworm disease, a life-threatening illness that can affect your pet’s heart and lungs. Heartworm testing allows us to determine if your pet is infected and create a treatment plan. Testing includes a blood test and other diagnostic tools, like X-rays. If you’re interested in heartworm testing for your pet, please contact us at 705-753-0324.

What is heartworm disease?

Heartworm disease happens when your pet is infected with heartworms, after being bitten by a mosquito. Dogs are more likely to get the disease, though some cats are diagnosed with it. Once in your pet’s body, the worms mature into adults who mate and create microfilariae, which are immature worms that circulate in the bloodstream. Heartworms look like long strands of hair and live in the right ventricle of your pet’s heart and pulmonary artery, which is responsible for carrying blood to the lungs. It typically takes 5 to 6 months for their life cycle to be complete. Heartworm infections are common in southern Ontario, with the highest risk of your pet contracting it during the warmer months.

How does heartworm testing work?

We diagnose heartworm infections with a blood test, running the samples in our in-house laboratory. The blood tests detect adult worms and microfilariae. The heartworm antigen test detects adult female heartworms between 6-7 months after your pet is infected. The test can detect as few as 1-3 worms. Microfilariae testing is also necessary to confirm an infection. A positive microfilariae test confirms that mature adult worms are in your pet’s heart, which informs the type of treatment your pet will receive to kill them.

What happens if my pet has heartworms?

If your pet is infected, we’ll develop a treatment plan to remove the worms and address any health issues created by the heartworms. Treatment usually involves two types of medication, one to kill the adult heartworms and the other to target the microfilariae. It’s usually effective, although there are some cases where small amounts of adult heartworms stay in your pet’s body after treatment.