Cat “cavities” don’t look like the holes you’d picture in a human tooth. Instead, they appear as soft, pinkish defects at or just above the gum line, often partially filled in by swollen gum tissue. These lesions are technically called tooth resorption, and they affect an estimated 20 to 60 percent of cats. Unlike human cavities caused by bacteria and sugar, tooth resorption happens when a cat’s own body breaks down tooth structure from the inside out.
What Tooth Resorption Looks Like
In the earliest stages, a resorptive lesion is easy to miss. It starts as a small pit or notch right where the tooth meets the gum, often less than half a millimeter deep. At this point, you’d need to look closely and might only notice a tiny spot where the tooth surface looks rough, pitted, or slightly pink compared to the surrounding white enamel.
As the lesion progresses, the gum tissue swells and grows into the defect, creating what looks like a pink or red bump on the tooth. This is one of the most recognizable signs: any area of gum enlargement along a tooth in a cat should raise suspicion. The tissue filling the hole is soft and often bright pink or red, contrasting with the hard white tooth around it. Some owners mistake this for food stuck on the tooth or a minor gum irritation.
More advanced lesions cause significant destruction of the tooth itself. At this point, the tooth may look broken or jagged, resembling a fracture rather than a cavity. In the most severe cases, the entire visible crown of the tooth dissolves away completely, leaving behind a smooth, gum-covered bump where the tooth used to be. Underneath that bump, the root may still be partially intact, hidden beneath the gum line.
Which Teeth Are Most Affected
While any tooth can develop resorption, the lower third premolars (the first cheek teeth on each side of the lower jaw) are the most frequently affected. These sit toward the back of the mouth, which makes them hard to spot during a casual look. You’re more likely to notice a lesion on a canine tooth or an upper premolar simply because they’re easier to see, but the lower premolars are where the process most often begins.
The Five Stages of Tooth Resorption
Veterinary dentists classify these lesions into five stages based on severity:
- Stage 1: A shallow pit extending less than half a millimeter into the tooth’s neck. Virtually invisible without dental instruments.
- Stage 2: Significant erosion into the tooth, but the inner pulp chamber (where nerves and blood vessels live) hasn’t been breached yet.
- Stage 3: The erosion has broken into the pulp chamber, which typically means the tooth is painful.
- Stage 4: Major structural damage. The tooth has lost its integrity, with large portions eroded away and the pulp exposed.
- Stage 5: The crown is completely gone. All that remains is a retained root fragment covered by a smooth cap of gum tissue.
Stages 1 and 2 often produce no obvious symptoms, which is why many lesions go undetected until a veterinarian examines the mouth under sedation. By stage 3, most cats are experiencing real pain, even if they hide it well.
Signs Your Cat May Have a Lesion
Cats are notoriously good at masking pain, so you may not see dramatic symptoms even when a tooth is severely damaged. The behavioral clues tend to be subtle. A cat with dental pain may start eating and then suddenly stop, sometimes repeatedly in the same meal. Some tilt their heads to one side while chewing, favoring the less painful side of their mouth. Pawing at the face or rubbing their cheeks against furniture more than usual are other common signs.
Personality changes can also signal a problem. A normally affectionate cat may pull away when you try to pet their face or head. Some become uncharacteristically irritable, especially when touched near the mouth. Drooling, dropping food, or a preference for wet food over dry kibble are all worth noting, though none of these signs is specific to tooth resorption alone.
Why You Can’t Diagnose It at Home
Even if you manage to lift your cat’s lip and spot a pink or red area on a tooth, you’re only seeing part of the picture. Many resorptive lesions develop below the gum line, completely invisible to the naked eye. Dental X-rays taken under anesthesia are the only reliable way to assess the full extent of damage, determine whether the roots are affected, and decide on treatment. A tooth that looks mildly affected on the surface can have extensive root destruction underneath.
This is why veterinarians recommend dental X-rays as part of routine dental cleanings, not just when a problem is visible. A cat with one resorptive lesion often has others developing on different teeth.
What Treatment Looks Like
There is no filling or restoration that works for feline tooth resorption. Unlike human cavities, these lesions can’t be patched because the body is actively dissolving the tooth from within. The standard treatment is extraction of the affected tooth. For teeth where the roots have already begun to fuse with the surrounding jawbone (a process that happens in some types of resorption), a crown amputation may be performed instead, where the visible part of the tooth is removed and the resorbing root is left to be absorbed naturally.
Both procedures are done under general anesthesia. Recovery is typically quick: most cats eat comfortably within a day or two, and many owners report that their cat seems happier and more energetic afterward, suggesting the tooth had been causing more pain than was obvious. Cats adapt well to missing teeth and eat normally even after multiple extractions.