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AIVetTree · Cat Oral Health Guide

Feline Tooth Resorption (FORL) — Signs and Detection

Written and reviewed by the VetTree veterinary team · Last updated July 19, 2026 · Reference information

Feline tooth resorption (FORL) is a common, painful condition in which tooth structure is progressively lost. It is reported in many cats aged 5 or older and can develop below the gum line, making it easy to miss. Dental radiographs are required for confirmation.

What is tooth resorption (FORL)?

In tooth resorption, odontoclasts progressively break down the tooth's enamel and dentin. As it advances, the tooth may fracture or become covered by gum tissue. The condition can be very painful and affect quality of life.

In numbers

  • Studies report tooth resorption in about 20–60% of cats, with some estimates reaching 3/4 of cats aged 5 or older. (Cornell Feline Health Center and other sources)
  • Radiological tests detect about 2.4 times more lesions than visual tests — meaning there are many that are not visible on the outside.
  • Studies have shown that purebred cats (about 70%) have a higher incidence than mixed cats (about 38%).

※ Numbers vary greatly depending on the study, group, and diagnosis method.

Signs to watch for

What to look forWhat it may mean
Red gums rise above the teeth at the border of the gumsAppears with gums covering the absorption area
Crunching and crackling sounds while eating, chewing on only one sideMay indicate dental pain
Drooling, dislike when mouth is touchedMay indicate oral pain
Some teeth are broken or missingAdvanced absorption

Why is it so easy to miss?

Tooth resorption often develops below the gum line and within the tooth, so an early lesion may not be visible. A photo or visual exam can only raise suspicion. A veterinarian uses dental radiographs to confirm the condition and plan treatment. Because tooth resorption can be painful, arrange an exam if you notice possible signs.

Frequently asked questions

How common is cat tooth resorption (FORL)?

It is common. Depending on the study, tooth resorption affects about 20–60% of cats and has been reported in up to 3/4 of cats aged 5 or older. Prevalence increases with age.

Can you tell just by looking at it?

Early lesions can be difficult to see because they often develop below the gum line. A visual exam or photo can only raise suspicion; dental radiographs are required for confirmation. Radiographs detect about 2.4 times as many lesions as visual examination alone.

Does tooth resorption hurt?

Yes. Tooth resorption can be very painful. A cat may flinch while eating, chew on one side, drool, or resist having the mouth touched. Arrange a veterinary exam if you notice these signs.

Sources