The previous Fully Vetted column focused on periodontal disease, which affects both dogs and cats. Today’s column will focus on feline tooth resorption, or “cat cavities,” which cause a dental malady that is much more common in cats than dogs.

Feline tooth resorptions, also known as feline odontoclastic resorptive lesions (FORLs) or cervical line erosions, affect approximately 50 percent of cats. They are most commonly seen in cats 5 years of age and older. These lesions consist of focal erosions on the surface of the tooth. Unlike most cavities in humans, they are usually located where the gum line meets the edge of the tooth.

Despite much research on the topic, the cause of tooth resorption remains unknown.

Five stages of tooth resorption (TR) have been identified. Stage 1
TRs only affect the enamel, which is the outer layer of the tooth. Affected teeth are usually minimally sensitive, and can generally be managed with a thorough cleaning and polishing, followed by regular tooth brushing.

Stage 2 TRs affect the enamel and the underlying layer, the dentin. Affected teeth have increased sensitivity, and usually require extraction before they become more severe.

Stage 3 TRs have penetrated the enamel and dentin, and have entered the pulp cavity. These lesions are very painful. Stage 4 TRs are characterized by teeth that are severely weakened and have lost most of their structure. Stage 5 TRs have caused resorption of the entire crown (visible portion) of the tooth. Teeth affected by Stage 3 through Stage 5 tooth resorption usually require extraction.

Cats affected by tooth resorption may drool, bleed from the mouth, have difficulty eating, or refuse to eat dry food. TRs are usually very small, and are often covered by gingiva, so they can be difficult to diagnose without a thorough oral examination performed under sedation or general anesthesia.

Although they are small, tooth resorptions can cause significant pain. The more these lesions advance in severity, the more pain they cause, and the more difficult they can be to remove. It is therefore important to have them identified and treated early, before they cause significant pain, and while affected teeth are relatively easy to extract.

Dr. Kelly Sulik owns and operates Animobile Mobile Veterinary Services in Tryon, N.C. She can be reached at animobiledvm@gmail.com.