Feline tooth resorption is a common & painful condition in domestic cats. Usually, it looks like the gingival tissue is growing into the tooth or is covering over the base of the tooth. Some teeth undergoing tooth resorption are not apparent until dental x-rays are taken. The exact cause of tooth resorption has not been definitively established.
Cats having had tooth resorption previously will very likely develop additional lesions in the future. For this reason, dental x-rays are essential to monitor these cats to allow for early diagnosis & prevention or elimination of pain.
Signs of pain can be very subtle in cats. Watch for the gingiva growing onto the tooth, excess salivation, tartar, gingival (gum line) bleeding (look for blood around the food and water bowls), gingival inflammation & difficult/decreased eating. Food preferences from hard foods to soft foods may be a sign of oral discomfort. Owners typically fail to realize their cat is painful until after the cat is treated for resorbing teeth and they have a happier and more playful cat.