Heartworms in Cats?!

A few weeks ago, one of our clients was confronted with the reality of heartworms in her cat.  It was a challenging case for both the owner and our clinic. The cat lived indoors only and was on a monthly flea preventative. The cat was a beloved companion and the owner did everything possible to return the cat to good health. 

After the cat’s death, an autopsy revealed that the cat died due to heartworm complications.  Two heartworm larvae were found.  One in the cat’s brain and one in the liver.  A heartworm infestation was not thought to be the cause of the cat’s vague symptoms of vomiting, lack of appetite, weight loss, and lameness; although almost all of these symptoms are also symptoms of heartworm disease.

The effects of heartworms in cats are different than in dogs. The following are five facts about heartworm disease in cats.

1. Indoor only cats are susceptable to heartworm disease.  Twenty seven percent of infected cats are indoor only.  Mosquitos get into the home through screened doors and open windows.
2. Tests to check for exposure to heartworms are not very accurate.  Half of the cats exposed tested negative within 6 months and all cats tested negative in 18 months.
3. Cats cannot be treated for heartworm disease like dogs can.  When the heartworm dies too fast, so does the cat.
4. Nearly 2/3 of heartworm positive cats have signs like coughing, wheezing, vomiting, difficulty breathing, rapid heartbeats, and weight loss.  These symptoms could also be due to several other diseases though.
5. Lungs are affected by the disease in the cat, unlike the dog where the heart is affected.   An asthma-like disease is the most common diagnosis.

The best defense is prevention.  There are several products that will protect against heartworms. Talk with your veterinarian to determine which is the best for your cat’s lifestyle and risk.  If your dog is on heartworm, why is your cat not?  Even cats who do not live with a dog can get heartworm.  All cats deserve to be protected.  

Dr. Pam Cuevas

LaGrange Park Cat Clinic

3075 S. Wolf Rd.

Westchester, IL 60154

(708)562-2287

cat.doc@lgpcatvet.com