Ask the Vet

New Heartworm Medication

A once-a-year preventative for heartworms in dog is now available. (PF photo by Victoria G. Myers)


I have heard there is a new once-a-year shot to prevent heartworms in dogs. Does it really work? Is it safe?


The ProHeart 12 injection is the once-a-year heartworm preventative you're talking about. It was approved and released in 2019. My practice actually participated in the company's clinical trials for ProHeart 12, and we have used it extensively for our clients' dogs since it came on the market. We were impressed with its safety during the trials. While it's new here in the U.S., the preventative has been approved in Australia since 2001. It is the most commonly used heartworm preventative in that country and, as such, has had an excellent safety profile with millions of doses given.