Chattering teeth can be a symptom of something very serious to your pets health. Shadow came to us after his owner died. He’s only 4 years old, but was recently diagnosed with a condition called stomatitis. Stomatitis affects about 10% of cats and is painful and debilitating. The exact cause is unknown. It causes severe inflammation of the entire mouth and leads to painful oral lesions and ulcers. In Shadows case, he needed full mouth extractions of all of his teeth. Symptoms to watch out for: �