What Are Heartworms?
Heartworms are parasites that live in an animal’s heart. They are transmitted to dogs and cats when an infected mosquito injects heartworm larvae which penetrate through tissue, eventually reaching the heart. There it grows to maturity and reproduces.

Can Cats Get Heartworms?
We used to think that cats rarely got heartworm disease, but new studies have been done indicating feline heartworm disease is much more prevalent than previously thought. Cats can be infected at any age and most heartworm infections consist of 6 or less adult worms. Though the disease is much more common in dogs, cats can also be infected by the heartworm parasite. Due to the small size of a cat’s heart, only one heartworm can cause significant illness.

What Are The Symptoms of Feline Heartworm Disease?
Signs of heartworm disease include, but are not limited to, coughing, lethargy, vomiting that is not related to eating, collapse, seizures and respiratory problems. Some cats show no early symptoms and can die without warning.

How Are Cats Tested For Heartworms?
Unlike dogs, testing for heartworms in cats can be very difficult due to the small number of worms usually present. The types of tests required to find out if heartworms are present include antigen (occult) testing with a small blood sample, x-rays, ultrasound, and angiograms.

Is There A Cure For Cats With Heartworm Disease?
At this time there is not an approved treatment for the removal of heartworms in cats, though different products are being studied. Veterinarians can, however, give infected cats certain medications to make them more comfortable.

Is There Preventative Available For Cats?
Fortunately, there are products that have been approved for cats which prevent heartworm disease. Medication is designed to be used monthly and we do not require cats to be tested before being started on medication. A product called Revolution is applied to the skin between the shoulder blades once a month. This product is absorbed nto the body and blocks the development of any mosquito- injected heartworm larva. It also prevents fleas, kills ear mites and controls roundworms and hookworms (intestinal parasites).
There is an oral medication, “Heartgard” which is in a formulation designed for cats. Feline “Heartgard” comes in two sizes - up to 5 lbs. and 5-15 lbs. The heartworm preventative that is used for dogs is NOT for use in cats, since the dosages are very different. Because of this, please do not give your dog’s heartworm prevention to your cat. Kittens can be started on feline heartworm prevention as early as 6-8 weeks of age.

Information compiled from the guidelines recommended by the American Heartworm Society