Q: I give my dog a chewable heartworm pill every month throughout the year. Can cats get heartworms? Should I give my indoor cat, Big Bertha, a heartworm preventive, too?
A: Yes, and yes.
Mosquitos, which transmit heartworms to dogs and cats in all 50 states, manage to get inside people’s homes, so even indoor cats should be protected.
Cats are relatively resistant to heartworms, so in a given geographic location, cats are infected only 5 to 20 percent as often as dogs. Still, cats need to be protected, because infection with a single worm or even just the immature heartworm larvae can cause serious disease and death. Moreover, the arsenic-like drug used to treat heartworm-infected dogs is fatal to cats.
A heartworm preventive will protect Bertha from this life-threatening disease that causes much more severe clinical signs in cats than in dogs. Monthly heartworm preventives are applied to the cat’s skin (Revolution or Advantage Multi) or given orally as a chewable tablet (Interceptor or Heartgard for Cats).
Infected cats can develop heartworm-associated respiratory disease (HARD), a chronic condition characterized by coughing and labored breathing. HARD, which mimics asthma and chronic bronchitis, often ends in death. Other infected cats die suddenly, without prior clinical signs.
Talk with your veterinarian about starting Bertha on a heartworm preventive this spring.
Lee Pickett, V.M.D. practices companion animal medicine in Pennsylvania. Contact her at email@example.com.