- Not a substitute for professional veterinary help.
Cat heartworm is a serious disease that can make cats very sick and can even be deadly. It’s caused by tiny parasites spread by mosquito bites. Even though cats are more resilient than dogs when it comes to heartworms, they can still get sick. A cat with heartworm might cough, wheeze, or have trouble breathing.
All cats can get heartworms, even if they never go outside. However, the risk is higher in places with a lot of mosquitoes.
Below, we talked to the experts to learn more about how cats can get heartworm, how to prevent it, and what to do if they start showing symptoms.
7 Symptoms of Heartworm Disease in Cats
Dr. Preston Turano, a veterinary advisor at Felix Cat Insurance, explains that most worms in cats don’t become adults. This means heartworm symptoms can range from mild to more severe and may include:
Sometimes, cats might also have trouble walking or have seizures. Sadly, these signs are often hard to notice until it’s too late to fix the damage.
What Causes Heartworm in Cats?
“When a cat is bitten by a mosquito that is carrying heartworm, the larvae are transferred to the cat’s bloodstream,” explains Dr. Haley Georges, Medical Director of Veterinary Emergency Group Arboretum.
These larvae grow and can get stuck in the cat’s heart and lungs over time.
How Do Vets Diagnose Heartworm?
Dr. Georges says if you see symptoms, take them to the vet.
Diagnosis can be tricky since respiratory issues are associated with many different diseases. Most vets will perform an antibody and antigen test, which detects the presence of two or more adult female worms.
Other tests your vet may administer include:
- Bloodwork
- Radiographs
- Cardiac ultrasounds
- Chest X-rays
How Do You Treat Heartworm in Cats?
Sadly, dog heartworm medicine can’t be given to cats. Instead, vets try to keep cats stable, manage their symptoms, and watch them to see if they get better or worse. The sooner heartworm is found, the better your cat’s chances of getting better.
Luckily, cats aren’t good hosts, so sometimes the worms go away on their own. Some possible treatments include:
- Medicine for swelling
- IV fluids
- Oxygen
- Antibiotics
- Surgery
Is it fatal?
Yes, heartworm disease can be fatal. Dr. Georges says since cats are so small, even a single heartworm can be deadly.
Thankfully, cats are better equipped to resist the infection than dogs, resulting in fewer fatalities. Even so, Dr. Georges recommends year-round heartworm prevention.
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How to Prevent Heartworm in Cats
The good news is that heartworm disease is nearly 100% preventable. The best way to prevent heartworm in cats is by giving them monthly preventative medication.
Prescriptions are available in pills or topical treatments. Some heartworm medications are also effective against other parasites like:
If you’re worried about the cost, you can get pet insurance with a wellness plan to help pay for it.
Finally, keep your cat inside, close windows and doors, and get rid of any standing water around your house to keep mosquitoes away.
Cat Heartworm FAQs
Can indoor cats get it?
Yes, indoor cats can get heartworm disease. Mosquitoes can still come inside through broken screens, open doors, and vents.
Are some cat breeds more prone?
All cat breeds can get heartworm disease. Their risk is higher if they go outside or live in a place with lots of mosquitoes.
Can cats spread it to each other?
Dr. Turano says heartworm disease is not contagious between cats or dogs.
Can humans get it from cats?
No, cats can’t give heartworm disease to humans—only mosquitoes can. Heartworm disease rarely affects humans.
