Tooth Resorption in Cats: A Painful Hidden Problem Explained

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Imagine a tooth slowly dissolving from within, yet your cat keeps eating as normal. That is tooth resorption, which affects a large proportion of adult cats. It has gone by names such as cat cavities or neck lesions, though it is not the same as decay in people, and it needs a different approach.

What is tooth resorption?

Specialized cells called odontoclasts, which normally remodel bone, begin to break down the tooth structure. The lesions often start at the neck of the tooth, near the gumline, and may extend into the crown and root. As the tooth erodes, the sensitive inner pulp may become exposed, which is very painful. In some teeth, the roots are absorbed and replaced by bone, and the crown breaks off, leaving a red bump of gum tissue.

How common is it?

Studies suggest that more than half of cats over about five years of age have at least one affected tooth. Many have several. It is one of the most frequently diagnosed dental problems in cats.

What causes it?

The cause is unknown. Theories include chronic inflammation, vitamin D levels, diet, genetic factors and mechanical stress. Cats with periodontal disease seem more likely to be affected. No single factor explains all cases. See cat dental disease.

Signs

Cats are masters at hiding dental pain. Subtle signs include:

• Chewing on one side, or dropping food.
• Drooling, sometimes with blood.
• Bad breath.
• A flinch or chattering of the jaw when the lesion is touched.
• Reluctance to eat hard food, or reduced appetite.
• Pawing at the mouth.
• Irritability or hiding.
• Red gum tissue growing over a lesion.

Many cats show no signs, which is why regular dental exams matter.

Diagnosis

The vet may spot lesions in the mouth, but about half of the damage is below the gum, and cannot be seen without X-rays. Under anesthesia, the vet probes the teeth and takes full-mouth dental X-rays. The X-rays show whether the root is being absorbed, and help decide the best treatment. See cat dental cleaning: what to expect.

Types

Vets classify lesions by stages, and by two types on X-rays. In one type, the root appears normal but the tooth is eroding. In the other, the root is disappearing. This helps decide whether to remove the whole tooth or only the crown.

Treatment

• Extraction. The standard treatment for painful lesions is to remove the affected tooth, including the roots if they are intact. Where roots have been replaced by bone and there is no sign of infection, vets sometimes remove only the crown.
• Pain relief. Local nerve blocks, and pain medication, are given.
• Monitoring. New lesions can develop in other teeth.

Fillings and other repairs are rarely successful, because the process continues.

After extraction

Cats usually recover quickly, and often eat better, and become more playful, once the pain is gone. Offer soft food for a week or so, and give medicines as directed. Return for a recheck.

Prevention

You cannot reliably prevent resorption, but regular dental checks and X-rays, good dental hygiene and early treatment of gum disease help. Brush teeth daily if your cat allows it. See how to brush a cat's teeth.

Senior cats

Because the condition is more common with age, senior cats benefit from regular dental assessment. See senior cat care guide.

Why X-rays are essential

Without X-rays, a vet can see only part of the picture. A tooth that looks normal above the gum may have a failing root. A tooth with an obvious lesion may have an intact root that must be removed completely, to avoid leaving fragments that cause pain. X-rays also show bone loss, abscesses and retained roots from previous extractions. Many vets now consider full-mouth X-rays part of a proper dental exam for adult cats.

What a painful lesion looks like

A resorption lesion often looks like a pink or red spot at the gumline, where the gum grows into the defect. It may bleed when touched with a probe, and the cat may chatter its jaw in response. Even small lesions can be painful. Since cats can hide this, a systematic exam under anesthesia is the best way to find them.

Cost and planning

Extractions raise the cost of a dental procedure. Ask your vet for an estimate that covers the possibility of several extractions. See cat vet visit costs and low-cost vet care for cats. Because lesions often progress, many cats need follow-up exams and X-rays every year or so.

When to see a vet

See a vet if your cat chews oddly, drools, has red gums or bad breath. Use the US vet directory to find a clinic.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.