Feline Tooth Resorption

Feline tooth resorption, formerly known as feline odontoclastic resorptive lesions and feline cavities, is the most common dental problem encountered in cats. Studies have shown that between 25-75% of all cats will develop this problem at some time during their lives, and they are more likely to suffer from this disease as they get older. Not only is this disease a problem with domestic cats, but it can be found in cheetahs, leopards and lions.

Diagram of a feline tooth

Signs of Tooth Resorption

Once the lesions progress, your cat may begin to show signs of pain when eating hard food. They may avoid hard food, or seem to chew hard food only on one side of their mouth. Often the cat will tilt its head while eating, drool, swallow kibble without chewing, or drop food. Touching these lesions can be very painful!

These lesions begin below the gum line and at first are only visible with x-rays taken during routine dental cleanings. As they progress, the lesions can move upwards towards the crown of the tooth, downwards towards the root, or in both directions.  As they move above the gum line, you may notice a bright red patch on the surface of the tooth where it meets the gum. The gum around the tooth can also become red and swollen.  If they move downwards towards the root, the tooth root can be destroyed.

Causes and Prevention 

Although we don’t fully understand why these lesions occur, we have some understanding of how they start and progress. For unknown reasons, tooth-destroying cells (odontoclasts) begin to attack the cementum layer of the tooth, a thin layer which normally binds the tooth to the jaw bone. From this point of attack, the cells spread into the dentin (inner layer of the tooth) and up towards the tooth crown and root. Since dentin makes up the bulk of the tooth root, the teeth roots begin to disintegrate. At the tooth crown, the dentin sits directly below the enamel. Once the enamel loses the support of its underlying dentin it can begin to chip off, or become resorbed by the same cells that attacked the dentin. At this point, the characteristic bright red lesions can be seen near the gum line.

Close up of the mouth of a cat with red lesions near the gum line

Unfortunately, the underlying cause of this disease is still not known, and there is no evidence that they can be prevented at this time. Regular dental checkups with x-rays are the best way to detect tooth resorption early on before it becomes a painful affair!


There is no known fix for feline tooth resorption, and the only treatment is extracting the affected teeth. When dental x-rays are taken, early tooth resorption can be seen. Although this early tooth resorption is not painful it almost always eventually progresses, so extraction is often recommended during routine dentals. For advanced cases, where the tooth root has been extensively re-absorbed, removing the crown of the tooth maybe the only option.

Written by Dr. Ira Froimovitch