Skip to content


The Pet Health Community and Pet Health Center are NOT substitutes for a vet visit. Contact a vet in an emergency! | Dog Conditions A-Z | Dog Symptoms A-Z | Cat Conditions A-Z | Cat Symptoms A-Z

Remember Your Beloved Pet
Includes Expert Content
Comfortis on cats
emerald3358 posted:
We have a stray cat that we are feeding in our backyard. She is wild but we hope to domesticate her and get her shots....etc. She is using our dog door to come into the house and we are worried about fleas. We have our dachshund on Comfortis. I cannot find a pill form of flea control for cats that lasts more than 24 hours (Capstar). She has not gotten used to us to the point of letting us touch her. I would like to give her the same Comfortis I give my dog, but have read it is not formulated for cats. How can it be that different?? Why will it not work?
Drew Weigner, DVM, ABVP responded:
While Comfortis is apparently safe for dogs, its toxicity in cats has not yet been determined. While it may turn out to be safe, cats metabolize many drugs differently than dogs. So until it's commercially available, I wouldn't use it in cats. Fortunately, there is another monthly oral flea treatment, Program, that is approved for use in cats.

Drew Weigner, DVM, ABVP
The Cat Doctor
Board Certified in Feline Practice
emerald3358 replied to Drew Weigner, DVM, ABVP's response:
Thank you for the information and for the name of an oral flea treatment for felines! We now know she has two kittens....triple the flea problem!! I'm sure we cannot give this to her kittens so we will have to work hard to get her (and them) used to us so we can get them cleaned up, shot up and spayed....

Thanks again!
clongest responded:
I actually found Comfortis for cats on the site, and as you said it works wonderfully on dogs, as my dogs have to go out for their needs, sometimes they may bring some fleas in the house and the cats get it. So I'm tented do give to my cats to get rid of this pest. I read many reviews, and it seams they are ok for cats.


Sandy Willis, DVM, DACVIM, is a small animal internal medicine consultant for Phoenix Central Laboratory, an independent veterinary diagnostic laborat...More

Helpful Tips

Helping Hospice Patients Keep Their PetsExpert
Pets are an extremely important part of our lives. And this is especially true when we are at the end of our days. What could be more ... More
Was this Helpful?
34 of 46 found this helpful

Report Problems With Your Medications to the FDA

FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Learn more about the AVMA

WebMD Special Sections