Skip to main content

What are heartworms, and what are the symptoms of heartworm disease?

Heartworm disease is a serious and potentially fatal disease caused by parasitic worms that live in the hearts of infected animals and spreads through the bite of an infected mosquito. Early symptoms of heartworm disease in dogs include a persistent cough, reluctance to exercise, fatigue, decreased appetite, and weight loss. In cats, early symptoms include a persistent cough, asthma-like attacks, periodic vomiting, decreased appetite, and weight loss. If left untreated, blockages in the heart can occur in both dogs and cats and can lead to life-threatening cardiovascular collapse as well as organ failure. This is why prevention is the best kind of treatment!

Is heartworm disease curable? How are heartworms treated?

Heartworm disease is curable, but treatments can be expensive, painful, and time-consuming. Heartworms in dogs are treated using the oral antibiotic doxycycline followed by two injections of melarsomine that will kill the actual worms. Since the injections need to be spaced out a month apart, the treatment takes around two months to complete and your dog can still be experiencing painful symptoms during that time.

Unfortunately, this same treatment regimen is unsafe for cats, and their treatment can take longer and become more invasive. To treat heartworms in cats it is essential to seek veterinary care that focuses on stabilizing your cat and creating a long-term treatment plan. Heartworm prevention is essential because it saves you and your furry friend time, money, and comfort by preventing infection in the first place.

How can heartworms be prevented?

To keep your furry companion feeling healthy and happy, you should use a veterinarian-prescribed, monthly preventative medication (typically a chewable pill) and get your pet tested for heartworms once a year. The test is conducted by taking a quick blood sample and testing for the presence of larvae. Regardless of the climate you and your pet live in, even if you hardly ever see mosquitoes, your pet can still be at risk. Starting and maintaining a preventative treatment plan is key to keeping your furever friend happy and healthy, so you can focus on the good stuff like trips to the dog park, cuddles, and playtime!


If you think your pet may have heartworm disease, call your veterinary office as soon as possible for testing and treatment.

For more information about heartworm disease, visit these resources: