Heartworms in cats

Question
Our family inherited a house cat who's around 9 years old.  The previous owner never had her on heartworm medication.  (We live in Phoenix, Arizona and have had our dog on heartworm meds since he was a pup.)  I want to get her tested at the vet.  But what I need to know from you before I go in is if she has hearworms, is it too late to get her on meds?  The cat is so sweet and I just dread hearing from the vet that it may be too late or that she'll need surgery.  I'd really appreciate your thoughts on this.  Thank you!

Answer
Hi Christine,

First it is very kind of you to take on this kitty, thank you for giving her a home - it is hard for adult cats to find new homes. Since she is already 9 years old and I assume she goes outdoors since you are asking about heartworm, I would advise not testing or treating her for heartworm. If she did have heartworm, there is no safe treatment in cats - the drugs that work for dogs are more likely to kill a cat so are about as risky as the disease itself. Healthy adult cats can actually develop some degree of resistance against heartworm if exposed, so she is probably not at great risk from heartworm disease compared to the risk of treating her if she were positive.

I would recommend an annual health exam and perhaps include a chest xray this year to see if there are any visible signs of heart disease. Watch for any signs of heart disease which include coughing, tiredness, rapid breathing, poor appetite, an enlarged belly, pale or bluish gums, and a rapid, weak pulse. Your vet can listen to her heart.

If you want to have her tested just so you know if she is positive, then you will know to watch her more carefull if she shows any signs of heart problems. However I do not recommend treating heartworm positive cats, other than treating the symptoms.

Here is more info on heartworm in cats:

http://www.sniksnak.com/cathealth/heartworms.html