Heartworm disease is a significant, year-round risk to our pets in Florida.  Our warm, humid climate, means that mosquitos carrying heartworm disease are capable of infecting our pets at any time of the year.

While most dog owners know that heartworm prevention is an essential part of dog ownership, very few of Florida’s cat owners realize that cats require heartworm prevention too.

How do cats become infected by heartworm?

Cats are infected by heartworm when they are bit by a mosquito that is carrying heartworm larvae.  Once bit, the heartworm larvae develop in the cat’s skin, fat and muscle tissue.  Approximately two months later, young heartworms emerge and travel via the bloodstream to the cat’s heart and large arteries of the lungs.

What can heartworm do to my cat?

Unfortunately, heartworm disease in cats can be fatal, and sudden-death may be the first sign that a cat is infected.

When young heartworms reach the heart and arteries of the lungs, the cat’s body usually responds with a severe immune reaction to try and kill the worms.  This immune response causes inflammation in the arteries, lung tissue and airways which can result in coughing, difficulty breathing, wheezing or vomiting.  Long-term damage to the lungs can occur.  Heartworm disease in cats can easily be mistaken for feline asthma.

Young heartworms that don’t die early on will grow to an adult size of approximately eight inches long and will survive for two to three years in the cat.  When the adult worms ultimately die, fragments of the worms can lodge in the lungs and blood vessels causing acute inflammatory events that can result in death of the cat.

Feline heartworms can also migrate to the brain, eyes and spinal cord, which can result in neurological signs in infected cats.

How common is heartworm disease in cats?

The Companion Animal Parasite Council reports that as many as 20.9% of cats in Florida have been infected with heartworm disease at some point in their life.    National rates of infection are reported to be between 12 – 15.9%.

My cat never goes outside, so why should I worry?

If you open your doors, then your cat is at risk.  It only takes one bite from an infected mosquito to infect your cat with heartworm disease.  Studies have found that 30% of heartworm-infected cats were indoor-only.

Is there a test for feline heartworm disease?

Because the cat’s immune system responds so strongly to the presence of heartworms, the tests we have for detecting heartworm disease in cats are not as good as they are in dogs.  False negative results can occur, which makes identifying infection in cats difficult.

How do you treat heartworm infection in cats?

Unlike dogs, there is no treatment for heartworm disease in cats.  If your cat is infected, your vet may prescribe steroids to try and reduce your cat’s inflammatory response to the heartworms.  Supportive care is really all that can be provided, although surgery to remove the worms is occasionally attempted.

So what can I do to keep my cat safe and healthy?

Fortunately, preventing heartworm disease in cats is easy, and it only costs a few dollars a month.  A topical or oral medication, used monthly, is all that is needed to keep your cat from becoming infected.

If your cat isn’t on a monthly heartworm preventative, please contact us at Palm City Animal Medical Center today.  We would be happy to answer any questions that you have about feline heartworm disease, and can help you choose a heartworm preventative that will work best for you and your pet.

Established in 1981, Palm City Animal Medical Center is dedicated to providing the best possible care for your pets. With focuses on compassionate care in surgery, physical therapy and rehabilitation, preventative medicine, extensive diagnostics, and emergency service, Palm City Animal Medical Center combines exceptional medical care with a caring philosophy for pets and their owners. For more information, call 772-283-0920, visit www.palmcityanimalmedicalcenter.com or find us on Facebook at www.facebook.com/PalmCityAnimalClinic.