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My cat's mouth sore won't heal. What could it be and what to do?

Updated on September 23rd, 2025

Pet's info: Cat | Domestic Mediumhair | Female | spayed | 11 years old

My cat has a sore on the side of his mouth thought to be a rodent ulcer, but the sore it is not responding to treatment (clavimox, depro medrol, steroid injection). What else could be this sore be and what other treatment options are there?

1 Answer

Most Helpful Answer

Dr. Heidi DVM, CVA, CCRT, CVTP, CVSMT, CVCH

Answered By Dr. Heidi DVM, CVA, CCRT, CVTP, CVSMT, CVCH

Veterinarian, Certified Veterinary Acupuncturist, Certified Canine Rehabilitation Practitioner

Published on January 10th, 2018

I'm so sorry that you are dealing with this with Vivian. The location is a little abnormal for a rodent ulcer, so I would probably recommend more dermatology diagnostics (especially in an 11 year old cat if she hasn't had problems with this before). That may include a skin scraping or cytology of the area or even a biopsy of the area. Sometimes challenging skin problems require a referral to a veterinary dermatologist for a diagnosis. You can find a veterinary dermatologist near you here.
https://www.acvd.org/tools/locator/locator.asp?ids=16_Find_Dermatologist
If all results still point to a rodent ulcer, there are other medications you can try that will suppress the immune system. I have included more information on feline eosinophilic granuloma complex below.
https://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=656
Good luck! I hope that was helpful. Thanks for using PetCoach.
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