Heartworm Prevention for Cats: What You Need to Know

Heartworm disease is a serious yet preventable disease in cats. Heartworm in cats involves an infestation of long hair-like worms that will multiply and eventually clog your cat's heart and pulmonary arteries, leading to death. When a cat is bitten by an infected mosquito that carries heartworm larvae, those larvae pass to the cat causing heartworm disease. Unlike heartworm disease in dogs, there is no FDA-approved treatment for this disease in cats.

Cat heartworm prevention is the best way to protect your cat from this dangerous and potentially deadly disease. Your kitten should begin heartworm preventative medications as early as eight weeks. Below, learn more about how to prevent heartworm in cats.

Signs of Heartworm in Cats

Cats often have no visible symptoms of heartworm disease, making it difficult to identify in the early stages. Some cats with heartworm disease may initially have very subtle signs, which gradually worsen over time. Common signs of heartworm in cats include:

• Asthma-like attacks
• Coughing
• Lack of appetite
• Weight loss
• Vomiting
• Difficulty walking
• Seizures or fainting
• Fluid accumulation in the abdomen.
• Unfortunately, affected cats will often act normally until they suddenly collapse or pass away.

If you notice any of these heartworm symptoms in your cat, promptly schedule a sick visit with BetterVet. Your BetterVet veterinarian will perform a thorough exam and obtain a full medical history. They may suggest a blood test to check for certain conditions.

Treating Heartworm in Cats

Cat heartworm prevention is essential, as no drug is approved to treat this condition in cats. The medication used to treat canine heartworm disease is extremely toxic to cats, causing serious and often fatal side effects.  

Therefore, once a cat has heartworm disease, the only treatment option is surgical removal of the worms. This is a specialty surgery that carries serious risks, so it is uncommonly performed. It is much more likely that your Bettervet veterinarian will suggest a long-term management plan to help make your cat as comfortable as possible.

Testing for Heartworm in Cats

The American Heartworm Society recommends that cats be tested for heartworms once per year. This test can be done through a simple blood test that your veterinarian will perform. Since cats with access to the outdoors have greater potential exposure to mosquito bites, this is especially important for them, but please remember that mosquitoes can and do enter homes, so no cat should be considered completely safe from heartworm disease. Even cats on preventative medications must still be routinely tested for heartworm, as no medication is 100% effective in preventing heartworm in cats. To test for heartworm disease, your BetterVet veterinary doctor will only need to draw a small blood sample. 

How to Prevent Heartworm in Cats

Preventing heartworm disease in cats is achieved by using monthly preventatives. Cats (both indoor and outdoor) should be on monthly medications that your BetterVet veterinarian can prescribe. 

Medications to prevent heartworm in cats come in topical gels or chewable tablets that must be administered monthly. Unlike in dogs, there is not yet an FDA-approved heartworm prevention shot for cats. During your pet's wellness exam, your veterinarian will discuss the best heartworm prevention methods for your cat's needs and the proper administration of the medication. Medications must be given properly and on time to achieve the most benefit. Heartworm prevention medications are not available over-the-counter.

Frequently Asked Questions

How do cats get heartworm?

Heartworm in cats occurs when an immature worm (larva) enters your cat's body  via a mosquito bite. Although heartworm in cats is not as common as in dogs, it is still possible for cats to become infected. When mosquitoes bite your cat, the opening in the skin allows the heartworm larvae to enter. 

How can an indoor cat get heartworm?

Heartworm disease is still a real concern for indoor cats. Indoor cats living in apartments may roam onto a deck or balcony at times, where they may be susceptible to mosquito bites. During the summer months especially, mosquitos can also enter the home and put indoor cats at risk for heartworm.

How do cats get heartworms even if they're not ideal hosts?

Cats are not natural hosts for heartworms, making them less susceptible to heartworm infections than dogs. This is because heartworms cannot thrive as well inside a cat's body. When larvae enter a cat, they often die before they become full-grown adult heartworms. Although not common, it is still possible for heartworms to develop in a cat's body, leading to disastrous consequences. Since, all cats with heartworm disease eventually pass away, they should be properly protected using preventative medications.

When should my cat start heartworm prevention medication?

Kittens are at the same risk of heartworm as adult cats. As such, it's recommended that kittens begin heartworm prevention medication around two months of age. Your kitten's veterinarian will determine a safe and appropriate dose of heartworm prevention medication based on their body weight. As your kitten grows, the medication dosage must be adjusted accordingly. Never use dog heartworm, flea, or tick preventives on cats as this can be extremely dangerous and life-threatening. A single drop of certain canine topical medications can be fatal to a cat.

Speak with BetterVet About Heartworm Prevention for Your Cat

Heartworm in cats is often misunderstood by pet owners, who believe this condition only affects dogs. However, all cats should be protected against heartworm with preventative medication and annual blood testing for heartworm. Even if your cat is exclusively an indoor cat, it's vital to ensure they're protected from this catastrophic disease.