Annual Heartworm Check-up Keeps ‘Spring’ in Pets’ Steps

Published 12:00 am Thursday, March 27, 2014

(StatePoint) Spring means many things to dogs and their owners. It’s time for longer walks and the shared exhilaration of playing “fetch” on the lawn. Even muddy feet from spring rains can be a pleasure.

For many pets and their owners, spring is also a time to visit the veterinarian for an annual heartworm check-up.

Veterinarian and American Heartworm Society President Dr. Stephen Jones offers answers to common questions about this spring ritual.

• My veterinarian is recommending a heartworm test, but my dog was just tested a year ago. Why does he need a test again so soon?

Your dog should have an annual heartworm test to determine if he became infected during the previous season.

It takes months before a dog with heartworm will test positive. So testing annually — usually at the time the prescription for his heartworm medication is being renewed — makes sense.

As with many diseases, the earlier heartworm can be diagnosed, the better the chances he will recover. If heartworm disease in a dog goes undetected and untreated, the worms can cause progressive and potentially fatal damage to his arteries, heart and lungs.

• If my dog is on continuous heartworm prevention, why does he need to be tested?

Annual testing ensures his prevention program is working. Heartworm medications are highly effective, but dogs can still become infected.

Why? A common reason is simple forgetfulness. Missing just one dose of a monthly medication, or administering it late, can leave a dog unprotected. Even if you do everything right and on time, it’s no guarantee.

Some dogs spit out their heartworm pills when their owners aren’t looking. Dogs have also been known to vomit heartworm pills or rub off a topical medication. Whatever the cause of missing or delaying a dose, any of these mishaps can put your dog at risk of heartworm infection.

• Do my cats need heartworm protection too?

Like dogs, cats get heartworm disease. And while cats are not as easily infected as dogs, it only takes one or two heartworms to make a cat very sick. That’s why the American Heartworm Society recommends year-round heartworm prevention for both dogs and cats.

Because heartworm disease in cats may or may not involve infection with adult worms, the diagnosis can be challenging. Veterinarians typically run heartworm blood tests on cats before putting them on medication the first time, but later rely on such procedures as chest x-ray or ultrasound to confirm diagnoses.

More information about heartworm disease and its prevention can be found at

Spring, summer, winter or fall — your pets need year-round prevention to keep them healthy and free of deadly heartworms. Seeing your veterinarian for an annual heartworm check-up is one of the best moves you can make to keep the spring in your pet’s step.


Photo Credit: (c) iStock