Every month the Companion Animal Parasite Council puts out a list of the top ten cities in the United States that show a significant increase in positive heartworm tests. This February, our very own Alexandria, Virginia was #2!! That means that in the dead of winter, mosquitos in our area are still active. The only treatment for feline heartworm disease is prevention. Learn more about how heartworm disease impacts cats and what you can do to keep your cat safe.

What is heartworm disease?
Heartworms are blood borne parasites that reside in the heart or large blood vessels of the infected animal. People tend to associate heartworm disease in dogs, but cats are at risk as well.

How do cats get it?
Heartworms are transmitted by infected mosquitoes. The mosquitoes ingest immature heartworm larvae by feeding on an infected cat or dog. The larvae will continue to develop in the mosquito over the next 10-30 days. Then when a mosquito feeds again on another unsuspecting cat or dog, the heartworms are injected through its mouth at the bite site. The larvae then migrate and continue to mature until they reach the heart and pulmonary arteries. Eventually as they reach adult hood they can reproduce – typically after about 6 months. Because mature worms live in the pulmonary arteries, the damage can put strain on the heart. Even with disease remission, there is often chronic scarring of the arteries and lungs.

How do you diagnose it?
Diagnosing heartworm disease in cats is harder than dogs because they typically have less worms and many worms do not survive until the adult stage. Single sex infections are common as well because heartworm testing only screens for adult female worms. So if you have a cat infected with immature worms, then they may come up heartworm negative because of the tests limitations. However, even 1 immature heartworm in your cat’s system can permanently affect a cat’s health.

How do you treat it?
While there are treatment options in dogs, there is no treatment in cats. The best treatment available is prevention! There are so few things in veterinary medicine that we can prevent but heartworm disease is one of them. Regular year round use of preventives like Revolution, Advantage Multi, or Heartgard can save your cat’s life. Heartworm disease is in every single state and with climate change on the rise and mosquito populations flourishing, the incident rate is likely to increase.

Does my indoor only cat really need prevention?

Absolutely! Mosquitos can get in our homes so easily, and they are lasting longer through the winter months. In February, our very own Alexandria, Virginia, was named number 2 on the top 10 cities in the US with an increase in heartworm positive tests. So often we’ll hear from clients that they stop preventives during the winter months, but this is proof that it just doesn’t get cold enough in Virginia for long enough. Prevention is required year round to keep your cat safe!