Heartworm disease is a serious, potentially life threatening disease in cats. The disease is transmitted by infected mosquitoes that bite the cat and inject the larvae of the heartworm parasite. In the cat, these larvae mature into heartworms in about 6 months. This transmission has to happen through the mosquito to the cat, not from cat to cat. The worms infect the blood vessels of the lungs and heart, causing damage.
There is no treatment approved by the FDA in the United States to treat heartworm disease in cats. The only therapy is supportive, in an attempt to help the cat survive the disease, which lasts 2 to 3 years.
The FDA has approved 4 treatments to prevent heartworm disease in cats: Heartguard for Cats, an oral tablet by Merial. Interceptor, an oral tablet by Novartis. Revolution, a topical by Pfizer. Advantage Multi for Cats, a topical by Bayer.
These 4 treatments do not prevent the infection of the cat by the larvae from the mosquitoes. The treatments kill the larvae in the cat when they are in a particular part of their 6 month life cycle, before they mature into heartworms. Ideally heartworm prevention should be given all year, since the success of the medication depends on killing the larvae at a particular part of its life cycle. Also mosquitoes can survive the cold months indoors and carry the infection to indoor cats even in the winter.
Giving the cat the heartworm prevention monthly should be as easy as possible.
The tablets need to be given with food so they can be absorbed and ideally they should be chewed up. The tablets can be divided into 4 pieces and mixed in with food. Usually reducing the amount of food at that meal and making sure the cat is hungry will let the medication be eaten without being noticed. Some cats like the taste of the tablets and look at them as a treat but they still need to be given with food. If the cat would vomit the meal, contact your vet for instructions on when to give the cat another dose of heartworm prevention.
The topical medications are placed behind the neck. This requires pushing back the fur and squeezing out the liquid directly onto the skin. The manufacturers recommend not getting the liquid on your hands or touching the cat for 2 hours. The medication is placed behind the neck so the cat cannot groom the area. If you have multiple cats, the cat getting treatment must be isolated from the other cats for 2 hours. This prevents them from grooming each other. These topical medications have the advantage of protecting against many other parasites other than just heartworms.
Heartworm disease in cats is widespread, life threatening, and preventable. Please protect your precious companions!
