Whiskers is a great example of a happy cat with no teeth!
Stomatitis in cats is a severe inflammatory disease of the oral mucosa with a multifactorial etiology. The initiating factor is likely an abnormal immune response to plaque bacteria. The largest plaque-retaining surfaces in the mouth are the teeth.
Stomatitis is very painful, and cats suffering from it are listless, not eating well, dropping food, vocalizing in pain, sometimes bleeding from the mouth, loosing weight, and generally unhappy.
Partial or full-mouth extraction is the current standard of care for stomatitis. The overall outcome is good, with 60-80% of cats greatly improved after surgery. For the patients that are partially responding to surgical management we can achieve long term control with medical management.
Even in the cases where the inflammation is not completely resolved, the clinical signs of discomfort are gone, cats eat better, gain weight, are more social and happy again. Very few cats are refractory to treatment, mostly due to a weak immune system.