My cat has crusty mouth corners. Is it a rodent ulcer or new issue?

This appears to be what is commonly referred to as a 'rodent ulcer'. The most common cause for these to pop up in cats is an allergy, typically to something in the food. Sometimes these will resolve in their own, however sometimes they can become infected, long lasting, and problematic. If they become very large and painful it can discourage the cat from wanting to eat. If this ulcer has been present for more than 2 weeks it is probably not going to go away on its own. At that time I would recommend taking you cat to the vet for treatment. Nathaniel may need antibiotics and an immunsuppresive drug like steroids or Atopica. If the lesions keep coming back he may need to be on an immunosuppressive long term and/or a hypoallergenic diet. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

Hello. Thank you for using PetCoach. So sorry that Max has not been feeling well. The lesion in the photo could be a rodent ulcer but I have honestly never seen one in a kitten this young. My first thought would be that this is a calicivirus lesion. Does he have any lesions/ulcers inside his mouth? Here is a link to an article about calicivirus in cats: https://vcahospitals.com/know-your-pet/feline-calicivirus-infection Many rodent ulcers do not go away on their own without treatment with steroids which is not indicated to do since he has been ill. Most calicivirus lesions will go away on their own within a few weeks. Hope this helps. If you have more questions feel free to post again. Best wishes.

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.

Rodent ulcers, or eosinophilic granuloma complex, are typically allergy related. Identifying and treating the underlying allergy is the foundation for treatment. Have Sophie examined by your veterinarian. Discuss allergy testing, hydrolyzed diets and food elimination trials. Your vet can dispense or administer steroids to decrease inflammation and antibiotics to treat any infection.

Hi there and thank you for using Petco Pet Education Center, formerly Petcoach to address your concern. Judging from the pictures, this does not look like a rodent / indolent ulcer. It is difficult to say because I cannot see the underside of the upper lip very well but the area you are referring to appears to be on the lower chin area. Rodent ulcers most commonly occur on the upper lip. What you are seeing could be feline chin acne. If this is chin acne, products with benzoyl peroxide for animals can help with the condition and also changing the food and water bowls to metal or ceramic if you are using plastic may help. Chin acne can be difficult to address and resolve 100% but in many cases, it will spontaneously resolve. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further!

Poor kitty! Unfortunately he needs to see a vet to be treated. This condition often requires oral or injectable steroids for treatment, which is not available over the counter. If cost is a factor in your ability to get him to the vet, you can refer to this site for ideas on how to help with the cost http://www.humanesociety.org/animals/resources/tips/trouble_affording_veterinary_care.html

Hello, I'm sorry you're having to deal with this issue. This looks like it could be what's called a rodent or indolent ulcer, but something called an eosinophilic plaque is also common. Sometimes steroids are needed other times in antibioticd and sometimes both steroids and antibiotics are needed. If you're not satisfied with your current veterinarian I would consider getting a second opinion or seeking out a cat only practice