All Creatures Veterinary Hospital
4549 HW 62 West
Mountain Home, AR 72653
Feline Heartworm Disease
Heartworm disease is a parasitic disease of dogs that has recently been shown to also affect cats. There is
currently much research being done on heartworms in cats to establish more information on how the disease manifests,
how to test for it in cats, and how to treat heartworm disease in cat. Recent studies show that cats are at risk of
heartworm disease wherever dogs are at risk, even though the risk in cats is much lower. Heartworms are transmitted by
mosquitoes, making both outdoor and indoor cats vulnerable.
Because cats are not the usual host for the worm, cats usually have fewer and smaller heartworms than dogs. They often do not exhibit clinical signs until the disease is considerably advanced. One heartworm in a cat is enough to cause severe disease and even sudden death. Clinical signs in cats are similar to signs in dogs and include persistent coughing, difficulty breathing, vomiting, and weight loss. However, most cats do not show signs of disease and often, life-threatening breathing difficulty or sudden death is the first and only sign of disease.
Testing for heartworms in cats is difficult. Cats usually harbor very few worms, which makes detection of the worms difficult with routine tests. Canine heartworm tests are unreliable in cats. Other lab tests can be run, or a presumptive diagnosis can sometimes be made from clinical signs and x-rays. Often, a diagnosis cannot made until a necropsy (autopsy) is performed and the heartworms are found.
Treatment of feline heartworm disease is also very controversial. Treatment with an adulticide can cause significant complications and even death. Without treatment, the risks of sudden death and lung damage remain.
Although not common in cats, feline heartworm disease can be life threatening if acquired. We know that it can be prevented with medications similar to those used in dogs. For these reasons, we recommend monthly heartworm prevention in cats. There are products available including Revolution, Interceptor, and Feline Heartgard, which are labeled for use in cats for the prevention of heartworm disease. If you're interested in heartworm prevention for your cat, ask your veterinarian to talk about taking this positive step in providing excellent health care for your cat.