Quick answer: Tooth resorption is one of the most common (and most painful) dental problems in cats, where the tooth structure is slowly destroyed and replaced by the body’s own cells. Cats hide the pain extremely well, so it is often found only on examination. Diagnosis needs dental X-rays under anaesthesia, and treatment is almost always extraction of the affected tooth, which brings fast relief.
If you have never heard of feline resorptive lesions, you are not alone, yet this is one of the most common dental conditions vets find in cats. The tooth quite literally dissolves from the inside or at the gumline, exposing sensitive nerves. It is genuinely painful, but because cats are so good at hiding discomfort, most owners have no idea anything is wrong. Understanding the condition helps you recognise the subtle clues and act before your cat suffers in silence.
What is tooth resorption?
Tooth resorption happens when specialised cells called odontoclasts begin to break down the hard tissues of a tooth: the enamel, dentine and root. Over time, these tissues are destroyed and replaced, sometimes by bone-like material. The process can start at the root, below the gumline, or at the neck of the tooth where it meets the gum.
As the lesion eats into the tooth, it eventually reaches the sensitive inner layers, exposing nerve endings. This is why resorption is so painful: the tooth is effectively decaying from within. The exact cause is still not fully understood, which means it cannot reliably be prevented; the focus is on early detection and prompt treatment.
Why it is so easy to miss
Cats instinctively conceal pain, showing weakness is a survival risk hard-wired into them. A cat with a painful resorptive lesion will usually keep eating and behave almost normally. The clues are quiet:
- Dropping food or chewing on one side of the mouth.
- Preferring soft food, or hesitating at the bowl then walking away.
- Drooling, sometimes tinged with blood.
- A sudden “chatter” or jaw spasm when the sore spot is touched: a classic sign during a dental exam.
- Pawing at the mouth or face-rubbing.
- A red, inflamed spot where the gum is growing over a lesion at the gumline.
- Withdrawal, irritability or weight loss over time.
Many cats show none of these at home, which is exactly why regular dental checks matter. Resorption often sits alongside other dental disease, so it is worth understanding periodontal disease in cats too.
Why assessment needs anaesthesia
Here is the crucial point: you cannot fully assess tooth resorption on an awake cat. Many lesions begin below the gumline, on the root, where they are completely invisible to the naked eye. The only way to find and grade them is with dental X-rays under general anaesthesia, which also allows the vet to probe each tooth gently and look beneath the gumline.
That is why proper diagnosis is part of a professional feline dental cleaning under anaesthesia, not a quick look in the consulting room. An anaesthesia-free “cleaning” simply cannot detect or treat resorption, and may give false reassurance that the mouth is healthy when it is not.
How feline resorptive lesions are treated
Treatment depends on the type and extent of the lesion, but extraction of the affected tooth is the usual and most reliable treatment. Once a tooth is resorbing, it cannot be repaired or filled like a human cavity: the structure is being destroyed, and leaving it in place means leaving your cat in pain.
A treatment visit at AVH Animal Ark involves:
- Pre-anaesthetic blood test (an add-on from $250, not included in the procedure price) to confirm your cat is fit for anaesthesia.
- Safe general anaesthesia with IV fluids and full monitoring.
- Probing and charting under anaesthesia to map lesions (with referral for dental X-rays, which we don’t perform in-house, where a case needs them).
- Extraction of affected teeth, with local nerve blocks and pain relief.
- Scale and polish of the remaining teeth using our iM3 GS Elite dental unit.
- A monitored, gentle recovery before your cat goes home the same day.
The relief is often dramatic. Owners frequently report that their cat becomes brighter, more playful and eats more enthusiastically once the painful tooth is gone: clear evidence of how much discomfort they were quietly tolerating.
How we help at AVH Animal Ark
As an ISFM Silver Cat Friendly Clinic, AVH Animal Ark Veterinary Group assesses and treats resorptive lesions under safe anaesthesia with gentle, low-stress Cat Friendly handling; where dental X-rays are needed to grade a lesion, we refer to a suitable facility. We are at Springleaf and Tampines, open 7 days a week. A cat dental scale and polish (including extractions) starts from $550, rising to around $1,000 for severe cases. Pre-anaesthetic blood tests are an add-on from $250 and are not included in those prices. You will get a personalised quote after examination. Because resorption affects senior cats too, you may find our guide on anaesthesia safety for senior cats reassuring.
Worried your cat is hiding mouth pain? Book a dental check at our Springleaf or Tampines clinic. Book an Appointment →
Frequently asked questions
Can resorptive lesions be filled like a cavity?
No. Unlike a human cavity, a resorbing tooth is being destroyed by the body’s own cells and cannot be repaired. Extraction of the affected tooth is the standard treatment.
Will my cat be in pain after the tooth is removed?
Pain is well controlled with local nerve blocks and pain relief, and most cats recover quickly. Removing the painful tooth typically makes them far more comfortable than before.
Can I prevent tooth resorption?
Because the cause is not fully understood, it cannot reliably be prevented. Regular dental checks are the best defence, as they catch lesions early.
How will the vet find the lesions?
By probing and charting each tooth under general anaesthesia, since many lesions start below the gumline and are invisible during an awake exam. Where dental X-rays are needed to grade a lesion, we refer to a suitable facility, as we don’t perform them in-house.
Medically reviewed by Dr Joyce Lauw, Veterinarian (University of Sydney, 2013); MANZCVS (Medicine of Cats); Certified Veterinary Acupuncturist, special interest in feline and internal medicine. Read Dr Joyce’s profile
Last reviewed: June 2026. This article is general information and not a substitute for a consultation with your vet.
References / Further reading