Excited Cats is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no extra cost to you. Learn more.

Treating Heartworm Disease in Cats: Can It Be Cured?

Finding out your cat’s been diagnosed with heartworm can be a shock. Heartworms are parasites that infect the heart muscle causing it to function incorrectly and even stop working. Unfortunately, despite treatment being available for dogs with heartworms, no drug treatment is currently available for cats. Worms that are dead or dying within a cat’s heart can cause a cat to die suddenly. However, this does not mean they can’t recover from them.

3 cat face divider

What Are Heartworms?

Dirofilaria immitis, or heartworms, are mosquito-borne parasites that live inside a cat’s heart, blood vessels, and lungs. They can infect dogs, cats, and ferrets and cause many problems, including heart failure, damage to other organs, and lung disease. They can also cause sudden death, so it’s much easier to prevent these worms from taking hold rather than risk your cat contracting them.

Despite cats not being as susceptible to heartworm infections as dogs, they will still thrive for up to 2 years inside a cat’s heart. Heartworms in cats can also cause signs you wouldn’t immediately associate with problems with the heart, including vomiting and weight loss.

scottish fold cat checked by vet
Image Credit: Pixel-Shot, Shutterstock

However, when adult heartworms die in a cat’s body, heartworm-associated respiratory disease or HARD can occur, meaning that at around 3 to 4 months after the cat is bitten by a mosquito infected with heartworms, it may begin coughing and struggling to breathe.

3 cat face divider The 3 Treatment Options for a Cat With Heartworms

Unlike dogs, there is currently no drug treatment available to treat heartworms in cats. More drastic treatments can be given, but they have a very poor success rate and don’t completely reduce the risk of sudden death. There are two main types of treatment for cats with heartworms:

1. Treating the Symptoms of the Disease

Supportive treatment of heartworm infestation in a cat can include oxygen therapy, fluid therapy, and consistent monitoring. Several treatment types can be included, particularly as heartworm causes inflammation and fluid buildup in the lungs.

Treatments such as steroids for the inflammation and diuretics to help relieve the fluid build-up in the lungs can help to stabilize the cat and improve their symptoms. However, because heartworms can survive in a cat’s body, the treatment can take several months and be very costly.

vet holding burma cat
Image Credit: Elpisterra, Shutterstock
thematic break

2. Surgical Removal of the Worms

Removing heartworms surgically from a cat’s heart may seem dramatic, but it’s one of the only options for cats with a severe infection. Only specialist veterinary surgeons can perform this procedure, and despite having a complete heartworm removal, studies suggest that almost 40% of cats may still die either during or after the procedure.

thematic break

3. Spontaneous Cure

A spontaneous cure is when a cat’s immune system gets rid of heartworms of its own accord. This can occur without the owner’s knowledge, as some cats carry heartworm with no symptoms. This isn’t common, and despite the cat curing itself with its immune system, the possibility of sudden death via inflammatory reactions in the lungs is still possible.

happy cat
Image Credit: islam zarat, Shutterstock

3 cat divider Why Are There No Drug Treatments for Heartworm in Cats?

There are currently no developed treatments or medications for heartworms in cats. There have been trials using dog heartworm treatments. However, these come with risks, including toxicity, acute heart failure, and sudden death.

If the treatment kills off the worms, there’s also the risk of acute pulmonary crisis. This means that the cat’s lungs can suddenly stop working or become so inflamed and full of fluid that they cannot receive enough oxygen due to dead or dying worms becoming lodged in the lung tissue.

sad looking cat lying on a table
Image Credit: avi_acl, Pixabay

Can I Prevent Heartworm in my Cat?

There is effective medication available for cats to prevent heartworms from taking hold. This medication is safe and easy to administer at home, meaning that monthly treatment with heartworm preventatives is cheap and effective and protects your cat from possible heartworm infestation.

All cats should be treated with heartworm preventatives, even those who live indoors; mosquitoes can easily get into the home, and it only takes one bite of an infected mosquito potentially pass on heartworms to your cat. Heartworm medication is often included in wellness packages of pet insurance policies, and you can speak with your veterinarian about the best options for your cat.

cat paw divider


Heartworms in cats cannot be treated with medication as they can be in dogs.

The treatments available for cats are either surgical removal of the heartworms from the cat’s heart or supportive treatment, which can last for months. Ultimately, prevention is much better than cure, and heartworm medication given monthly is an easy, cheap, and effective way to protect your cat from any possible heartworm infestation.

thematic break

Featured Image Credit: Pressmaster, Shutterstock