Severe, recurrent, refractory gingivitis in cats can progress to a syndrome called stomatitis. In feline stomatitis the mouth becomes severely inflamed (irritated). Feline AIDS and feline leukemia virus may trigger stomatitis, but most cases occur for unknown reasons.
Cats with stomatitis have immune systems that reject their own teeth. For this reason, extracting multiple teeth may cause the inflammation to go away. In my experience, this sort of procedure is effective about 85% of the time.
Some mild cases of stomatitis can be managed with medicines that modulate the immune system. Prednisone and cyclosporine are the most commonly used. Prednisone, in particular, may cause unpleasant side effects.
Although extracting multiple teeth sounds extreme, remember that if the gums around the teeth are severely inflamed the teeth are painful and aren’t being used. In my patients, one complication of multiple tooth extraction procedures is weight gain. After the painful teeth are removed, some cats begin to over eat!
You can read much more about stomatitis here:
And you can read about milder gingivitis and dental disease here:
About the photo: Sylvester is showing off his dental arcades. There is no sign of stomatitis!