Prevalence estimates vary with the ages of cats studied and investigation methods, so one percentage range cannot be applied to every cat over 5. Pain also depends on lesion location: a change confined to the root surface may cause no symptoms, while a lesion exposed to the mouth and approaching the pulp can be very painful.
When to see a vet urgently
Contact a vet promptly if you notice any of the following:
- Your cat stops eating or tries to eat but drops food from its mouth.
- There is obvious oral bleeding, increased drooling or a marked pain response when the mouth is touched.
- Facial swelling or clear deterioration in general condition accompanies oral symptoms.
Other oral diseases can also cause these signs, which need examination. You can find a vet near you.
Overview
Normally, a cat's teeth remain strong throughout life. Resorption starts a process of hard tooth tissue breakdown. Over time, lesions develop in crowns or roots and may destroy the whole tooth. Premolars and molars are most often affected. The process is chronic and worsens with age.
The visible part is called the crown and the part within the jawbone the root. Dentine makes up much of the tooth, and the pulp inside contains blood vessels and nerves. During resorption, cells that break down hard tissue gradually remove the tooth. This is different from ordinary human tooth decay.
Changes often begin around the root, so a small visible gumline lesion may be only part of the problem. If the crown breaks away completely, root tissue may remain below the gum. An apparently missing tooth therefore does not show whether the problem has gone or continues out of sight.
Causes
The exact causes of tooth resorption are not fully understood, but recognised risk factors include:
- oral inflammation, including gingivitis and periodontitis
- disturbances of calcium and phosphorus metabolism
- inherited susceptibility, more often in Siamese, Abyssinian and Oriental breeds
- age-related changes
- immune system disorders
Inflammation can be associated with certain forms of resorption, but the trigger for many spontaneous lesions remains unknown. The metabolic, immune and individual breed factors listed should not be interpreted as proven causes in every cat. Altering calcium, phosphorus or vitamin D on your own is not an established treatment for resorption.
Risk factors
Tooth resorption occurs more often in cats that:
- are over 5 years old
- are pedigree cats, particularly Oriental and Siamese cats
- have chronic gingivitis and tartar
- have other dental problems
Age increases risk, but young cats can also have lesions. Increased risk in pedigree cats has been reported, but the relative importance and causal relationships of every listed factor are incompletely understood. Gingivitis and resorption can occur together, but resorption may also occur without obvious gum inflammation.
Main symptoms
Early disease may be unnoticed. Typical signs include:
- pain when eating, with refusal of dry food or slow chewing
- increased salivation
- blood around the gums
- bad breath
- red, inflamed gums around a tooth
- a tooth breaking or being destroyed
- reduced play and activity because of pain
A cat can retain its appetite while having oral pain. It may swallow biscuits without chewing, tilt its head or use only one side of its mouth. An empty bowl alone therefore does not show that the teeth are healthy.
When watching symptoms, consider how your cat eats and any change in food preference too. You do not need to poke a tooth at home to confirm the diagnosis, as touching a lesion can hurt. A vet's visual inspection while the cat is awake is only the start of investigation.
Complications and consequences
Without treatment, tooth resorption leads to:
- complete loss of affected teeth
- chronic pain and stress
- spread of oral infection
- a risk of infection in internal organs, including the heart, kidneys and liver, through bacteria in the bloodstream
The relationship between oral inflammation and systemic health is complex. The organ infection risk mentioned above should not be interpreted to mean resorption itself has been proven to cause heart, kidney or liver infection. Evidence of a direct causal relationship between oral bacteria and distant organ diseases is limited. Pain and difficulty eating are sufficient reasons for treatment in themselves.
Diagnosis at the vet
Diagnosis is confirmed through:
- visual oral examination
- dental X-rays, essential for detecting root lesions
- dental examination under general anaesthesia
X-rays also show what lies below the gum
Intraoral dental X-rays show roots and surrounding tissues more precisely than visual inspection alone. Imaging the whole mouth can reveal changes in other teeth that neither owner nor examiner can see on the crown surface. Lesions are therefore not all alike even in the same mouth, and treatment is assessed for each tooth separately.
Resorption type describes the root and its attachment as seen on X-rays. The stage instead describes how much hard tooth tissue has been lost. These are different classifications. A red gumline alone is insufficient to decide whether roots also need removal.
General anaesthesia is needed for careful examination, imaging and treatment. Gum pockets, fractures and other painful changes are assessed too. Before anaesthesia, general health, current medicines and previous anaesthetic experiences are reviewed. Additional tests are chosen individually.
Treatment
Fillings cannot stop resorption: the affected tooth continues to break down and remains painful. Based on dental X-rays, the vet therefore:
- removes the whole tooth if roots remain, in type 1 resorption;
- may remove only the crown if roots have been replaced by bone, in type 2;
- treats pain and monitors other teeth, as resorption often develops in additional teeth.
Crown removal alone suits only carefully selected cases. X-rays must show advanced root replacement, and there must be no periodontal inflammation, root-tip inflammation in that tooth or stomatitis in the cat that would prevent this approach. A type 1 root is not deliberately left in the jaw under this method.
A filling does not stop resorption already under way. Antibiotics or tartar removal alone do not repair destroyed tooth tissue either. For some findings confined to the root, not exposed to the mouth and without symptoms, the vet may choose monitoring. This differs from leaving a painful tooth untreated.
All procedures take place under general anaesthesia. Annual oral examination with dental X-rays helps identify affected teeth before they become very painful.
A safe procedure and recovery
Vital functions are monitored during anaesthesia and the airway is protected appropriately. Local anaesthesia can be used alongside other pain relief. Old age alone does not mean dental care is impossible; risks are assessed against the cat's diseases and the harm of untreated pain. Cleaning visible surfaces without anaesthesia does not replace this investigation or treatment.
Home instructions cover pain relief, feeding and monitoring the treated area. Report if your cat does not eat or pain signs continue. As healing progresses, food handling and general demeanour may change, so previously unnoticed pain may only become apparent to you when your cat improves.
Treating one tooth does not provide permanent protection for the whole mouth. New lesions can develop in other teeth, and further examinations are planned according to findings. The need for follow-up X-rays is assessed particularly in a cat with established resorption.
Prevention
Tooth resorption cannot be completely prevented, but risk may be reduced through:
- regular toothbrushing and oral hygiene
- professional checks 1–2 times a year
- timely tartar removal
- regular dental monitoring in pedigree cats
Brushing and plaque control support the gums and tooth-supporting tissues. However, they do not reliably prevent resorption arising for unknown reasons. Discuss suitable dental care equipment with the vet, and do not forcibly brush a painful mouth. Identified painful lesions are treated before starting home care.
Check-up frequency is adapted to the findings. A healthy-looking crown or little tartar does not rule out a root lesion, so home inspection does not replace necessary X-rays. Resorption also does not show that the owner has neglected brushing.
What it means for owners
Tooth resorption is one of the most common feline dental problems, causing severe pain and reducing quality of life. Regularly check your pet's teeth and seek a vet with dental expertise promptly when the first symptoms appear.
Frequently asked questions
Can a cat eat normally despite tooth resorption?
Yes. Many cats keep eating and change only how they chew. Swallowing biscuits whole, tilting the head or dropping food can indicate pain. Do not wait for a cat to stop eating before arranging an oral examination.
Why is the whole tooth sometimes removed, but only the crown in other cases?
The choice depends on root condition on X-rays and other oral diseases. If root tissue remains distinguishable as normal or is inflamed, crown removal alone is generally insufficient. Crown amputation is a carefully selected treatment, not a shortcut around examining roots.
Can brushing prevent tooth resorption?
It helps prevent plaque-related gum disease, but no reliable means of preventing resorption is known. Painful teeth are not treated with brushing alone. Previously identified resorption warrants planned further oral checks.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Tooth Resorption, Cornell Feline Health Centre, accessed 2026-11-03.
- Tooth Resorption in Small Animals, Merck Veterinary Manual, accessed 2026-11-03.
- Feline Tooth Resorption (TR), American Veterinary Dental College, accessed 2026-11-03.
- Feline Dental Disease, Cornell Feline Health Centre, accessed 2026-11-03.
- Anaesthesia, sedation, and analgesia considerations, American Animal Hospital Association, accessed 2026-11-03.
- Pet dental care, American Veterinary Medical Association, accessed 2026-11-03.
- Clarification of the impact of periodontal health on systemic health, American Animal Hospital Association, accessed 2026-11-03.