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Why is my cat's mouth corner red and irritated? Ulcer or FCV?

Updated on September 23rd, 2025

Pet's info: Cat | Domestic Mediumhair | Female | spayed | 10 years and 10 months old

The corner of my cat's mouth has been red/irritated for over a week. It looks generally the same as it did a week ago and isn't getting worse. Last night he started sneezing intermittently and he has vomited some food two times over the last three days. His appetite and energy levels seem normal. There is no eye discharge. He has not been exposed to other animals. Is it possible the the the redness in the corner of his mouth is an ulcer? Does this sound like feline calicivirus?

1 Answer

Most Helpful Answer

Answered By Daniel Fonza, DVM

Veterinarian

Published on November 8th, 2017

Hi there and thank you for using pet coach to address your concern. Based on the picture in your description I would not think this is feline calicivirus. Feline calicivirus is mainly manifested as upper respiratory symptoms. I would think that this is an ulceration due to a complex disease associated with the immune system. Cats can develop ulcers on the lips due to a disease called eosinophilic granuloma complex. Many times these ulcers in the lips are due to an allergic response. If you are using plastic bowls to feed from I would switch to ceramic or metal to help prevent this. If you are already using ceramic or metal bowls then this may have been any different allergy trigger from the environment. Many times treatment with a steroid will help resolve this and sometimes this will only pop up once during the year or several times. If this is not getting any better or it is worsening I would suggest having your veterinarian take a look at this to recommend the most appropriate treatment. I hope this helps guide you in the right direction. Please feel free to contact me with any other questions or concerns you may have

7Pet Parents found this answer helpful

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