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We “Heart” Cats and So Do Heartworms

We “Heart” Cats and So Do Heartworms
May 16, 2022

It’s a silent killer that has no cure, but it’s easily prevented. We may think of heartworm disease as a dog problem, and while more dogs than cats contract heartworms, mosquitoes find cats just as tempting of a meal as they do dogs. One shelter found during a year-long study that 26% of cats had been infected with heartworm larvae at some point in their lives, with 10% of heartworms making it to adulthood. This may not seem like enough to cause alarm, but when you compare that to Cornell University’s findings that FIV has an infection rate of 1.5-3% and feline leukemia infects 2-3% of the healthy cat population, you can see that feline heartworm disease is a much bigger problem than many think.

How Does a Cat Get Heartworms?

You may be wondering, what do mosquitoes have to do with heartworms? In a word: everything. Mosquitoes are carriers of heartworm larvae, and it only takes one bite to infect your cat. When your cat is bitten, the larvae enter the cat’s system through the wound. Not all of these larvae will develop into adult heartworms, but both larvae and adults cause inflammation or damage to blood vessels. Heartworms and their larvae mostly affect the lungs in cats, but they can even be found in the body cavities, arteries, and central nervous system.

Why Isn’t There a Cure for Heartworm Disease in Cats?

As mentioned before, if your cat contracts heartworms, there is no cure. That’s because the treatment that is used for dogs is toxic to cats, so prevention is critical. Cats differ substantially from dogs in how their bodies react to heartworms; the cat’s immune system attacks heartworms and can kill them. That sounds like great news, right?! This is part of the reason why the disease is more acute in cats, and much more likely to be fatal. When the adult worms die, it puts your cat at a high risk of death, even spontaneous death before symptoms even appear.

What Symptoms Will My Cat Have?

Heartworms are more difficult to detect in cats than they are in dogs. By the time symptoms manifest themselves the disease has already progressed substantially, and when this is combined with the fact that cats just naturally hide illness better than dogs, you’ve got a major problem by the time your cat starts to cough, wheeze, pant, or show other signs of respiratory distress; symptoms that are easily confused for asthma. Blood tests, X-rays, and/or ultrasounds may be required to find where heartworms are lodging.

Other symptoms include intermittent vomiting, gagging, diarrhea, loss of appetite, weight loss, and lethargy, which again, are easily attributed to many other ailments. Once detected, supportive therapy is an option to help keep your kitty as comfortable as possible, but there is just no substitute for regular monthly prevention.

Do Indoor Cats Get Heartworms?

But if your cat doesn’t go outside, they’re safe, right? Wrong. Mosquitoes might as well be indoor-outdoor pets in Florida—we provide them with a safe place to live and plenty of food; no wonder they won’t leave once they get inside our homes! What’s more, researchers have found that around 27% of heartworm-positive cats were indoors only.

What Can I do to Prevent Heartworms?

In short, heartworm disease is much less common in cats than it is in dogs, but it’s a much more severe disease for our feline friends. And with no good treatment option, we can see why heartworm prevention is so important for cats. There are many options when it comes to heartworm prevention, from topical to oral tablets, and some provide protection from fleas and intestinal parasites as well. We’d be happy to help you decide which is best for your cat.

Northeast Animal Hospital