You & Your Pet by Dr. Wise

Rhode Island Veterinary Medical Association 11 South Angell Street #347 · Providence, RI 02906 (877) 521-0103 (866) 277-0238 Toll-Free ·Fax

Sidney, my perfectly healthy 8-year-old male cat, suddenly died last week.  He had a seizure and died before I could get him to my veterinarian.  I thought he had been poisoned since he was outside a lot.  My veterinarian did an autopsy and found that Sidney had heartworms.  I never knew cats could contract heartworms.  I give my dog heartworm preventative medicine.  Is there a preventative medicine that I can give to my other cats?

I am so very sorry to hear about Sidney's sudden death.  Unfortunately, your story is all too typical for cats with heartworms.  Heartworms in cats is indeed a problem in all areas where heartworms are found in dogs.  Mosquitos, the host that transmits heartworms, bite cats just as they bite dogs.  Cats have been known to die from an infection with only one worm.   Cats appear to develop a more severe allergic reaction to the heartworm parasite than dogs do. 

Veterinarians have known for a long time that cats can get heartworms, but until recently, we did not believe it was a very common problem.  Consequently, we have not stressed the importance of preventative medicine for cats.  Part of our reluctance was because simple, reliable tests were not available to diagnose the problem.  And until recently, heartworm preventative medicine approved for use in cats was not available.

If you live in an area where dogs get heartworms, your cat should also be on preventative medicine, especially if your cat gets outside.  An easy-to-use applied heartworm medicine was introduced last fall.   Ask your veterinarian what he or she would recommend for your cat.

This information, prepared as a public service by the Rhode Island Veterinary Medical Association, answers problems Rhode Island veterinarians currently are seeing in their practices, as well as new developments in animal care.