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What causes my cat's recurring rodent ulcer and swollen lip?

Updated On September 23rd, 2025

Pet's info: Cat | Siamese | Female | spayed | 1 year and 10 months old | 10 lbs

My cat has Rodent Ulcer that comes back every so often and I have had her for about two months. Before I adopted her they warned me to watch if it comes back and it did. They said the cause could be from stress or allergies, I found the Authority Sensitive food and she seemed to be okay with it and I mixed E.Colloidal Silver with wet food (same brand) to help her. It went away 2 weeks later and I recently switched her wet food and it looks like her lip is starting to swell. What is the cause?

1 Answer

Most Helpful Answer

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Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on August 2nd, 2018

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.

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