County Animal Hospital

Heartworm Prevention in Dogs   Heartworm Prevention in Cats    Heartworms are spread by mosquito bites. The adult heartworm lives in the heart and the blood vessels leading to the lungs. It can be fatal to your dog. All dogs should be on heartworm preventation. Milbemycin is the recommended product. It is available as a monthly chewable tablet marketed as Interceptor and in combination with a flea preventative as Sentinel. Interceptor or Sentinel should be given monthly all year. Dogs older than 6 months of age should have an annual heartworm blood test.   Diethycarbamazine is an older product that is given daily from April through December. It is sold as Nemacide in tablet and liquid formulations and as a daily chewable called Filarabits. Nemacide is the least expensive form of heartworm preventative. Filarabits is comparable in cost to Interceptor. It is of paramount importance that dogs given Nemacide and Filarabits have a heartworm blood test before resuming their medication each spring. Heartworm Prevention in Cats: Heartworm is primarily a canine disease but cats can be infected as well. Feline infections are a accident as far the the heartworm is concerned because the parasite is rarely able to develop properly in the cat. Nevertheless, these infections can be very serious for cats and are believed to be an under-recognized cause of feline lung disease. Cats have smaller hearts and pulmonary arteries thando most dogs so even a single heartworm can cause serious disease in a cat.Heartworm treatment in cats is too dangerous to attempt. Palliative therapy with cortisone (prednisone) is usually the best choice with the hope that the cat will out-live the parasite. It is, therefore, recommended that cats be placed on heartworm preventative just like dogs. The same Interceptor tablets that are dispensed for dogs are now prescribed for cats. The feline dosage is higher due to differences in the way cats absorb the milbemycin from the intestine. Cats tolerate the medicine very well with no reported side-effects. Cats that go outdoors are at the greatest risk, but no house is mosquito-proof so all cats should be on preventative. Copyright ©1999-2000