Expert: Jessica - 10/10/2010

Question
My cat is 5, strictly indoor, fixed, overweight, declawed. I noticed two days ago her upper lip, just from under her nose to lips was very dark pink (not red) and swollen.  She also had a scab on the outer edge of her mouth.  The scab is now gone, but her upper lip, directly above her front teeth, is swollen and very hard. I get food from a food bank, the only thing different that coincided with this, was I gave her some wet food out of a can I got there that was dented. It looked/smelled fine.... but this is the only different thing she's had, she's been on Purina dry food always, with occasional amounts of wet food, and bits of tuna for a treat.  She doesn't normally eat leftovers/junk food.  Do you think this will go away?? I really don't have $$ to take her to a
Vet.  She did throw up 3 times the day after she had the different wet food. She doesn't appear to be in pain, appears to be eating/drinking/ using litter box normally.  Do you have any ideas?  She's NEVER been ill before... has had all her shots and is fixed.  Thank you very much for your help on this site.  Anne

Answer
Hi Anne,

This might indicate an allergic reaction, and while it's uncommon for cats to have this type of a reaction to food, it is possible.  Since it seemed to occur around the time you gave her the food, there is a possibility the food is the cause.

However, I'm wondering if it might be a coincidence, because what you seem to be describing sounds very much like an eosinophilic granuloma, or "rodent ulcer".  This is a thickening and sometimes ulceration of the tissue around the mouth, very often on the inside of the upper lip.  Tough granular tissue replaces normal soft tissues, and the area often become painfully swollen and ulcerated.  It's not fully understood why.  It's believed to be an auto immune disease, or perhaps related to allergies.  Some suspect it's caused by flea allergies.

What is known is that cats generally respond to a corticosteroid treatment, such as cortisone, and this would be the same treatment to immediately treat a food-related allergy exposure.  One shot will generally reduce the inflammation and keep the condition under control for quite some time.  In severe cases, immunosupressant drugs may be required, or surgery may be necessary to remove permanently damaged tissue.  However, this is quite uncommon.

Because granular tissue just tends to keep forming and scarring without treatment, I would recommend that the kitty be seen by a vet if at all possible.  There are other possibilities, such as an oral infection that would require an antibiotic to clear up or even squamous cell carcinoma, as well, so only a vet could tell you for sure what's going on with your kitty.  They all should be treated by a vet, however.

Best of luck!

Jessica