Feline resorptive lesions (i.e., FORLs, or tooth resorption) are a common and painful condition and occur when the bony structure of the tooth erodes, leaving the sensitive pulp exposed. Tooth resorption affects up to 75 percent of cats age 5 or older. Our team at Colony Veterinary Hospital explains this painful condition, including clinical signs, diagnosis, and treatment.

What is tooth resorption in cats?

Feline tooth resorption is a dental condition characterized by the erosion of the hard tissue beneath a tooth’s enamel (i.e., dentin). Despite being relatively common, the condition has no known cause. The predominant theory suggested by some researchers holds that an excess of vitamin D in cat food may be to blame. Factors that may contribute to resorptive lesion development include:

  • Genetics — Certain breeds, such as Siamese and Persians, are more prone to feline resorptive disease.
  • Diet — Feeding your cat a diet that lacks essential nutrients may contribute to dental problems.
  • Oral hygiene — Poor dental care and a lack of regular teeth cleaning can increase tooth resorption risk.
  • Age — Older cats are more susceptible to this condition.

What are the signs of tooth resorption in cats?

Cats tend to hide illness or injury signs, which can make it difficult to identify early indications of tooth resorption. Potential signs include:

  • Red or swollen gums — Gingivitis is one of the earliest dental disease signs and can indicate inflammation and infection.
  • Bad breath — Foul-smelling breath is often linked to oral bacteria and dental disease.
  • Difficulty eating — If your cat is reluctant to eat, drops food while eating, chews on one side of their mouth, or swallows without chewing, they likely have dental issues. They may also refuse to eat dry kibble and want soft canned food.
  • Excessive drooling — Increased salivation is a sign of oral pain.
  • Pawing at the mouth — Cats often paw at their mouth when their teeth are painful.
  • Behavior changes — Your cat may shy away from handling and petting around their head, hide more, and be less playful.

However, some cats may show no clinical signs despite their intense pain, which makes regular oral care—including dental cleanings and X-rays under anesthesia—the best way to identify and address resorptive lesions.

How is tooth resorption diagnosed in cats?

Resorptive lesions are often hidden beneath tartar or gum overgrowth (i.e., gingival hyperplasia), and they are impossible to identify until the cat is under anesthesia. The lesions are often found along the premolars and molars, but can also affect any tooth, including the more prominent canine teeth. The lesion will look like an overgrowth of gum tissue, but in fact the tooth’s dentin has eroded, leaving the sensitive pulp exposed. Once the severity of the damage has been determined, your veterinarian can make an appropriate treatment plan.

How is tooth resorption treated in cats?

Tooth resorption is a painful and irreversible dental condition, and while restorations (i.e., fillings) can be performed in the early stages of the disease, they are usually temporary, as the disease process is progressive and continues underneath and around the fillings. Treatment most often involves removal of the affected tooth. In many cases, cats will need full-mouth extractions. Despite treatment, future resorptive lesions may recur, but if, when, or where is impossible to predict. Cats with resorptive disease should have oral exams, dental X-rays, and dental cleanings every six months to prevent unnecessary pain.

Can tooth resorption be prevented in cats?

Because tooth resorption in cats is poorly understood, it cannot be prevented. However, you can take proactive measures to safeguard your cat’s overall dental health.

  • Dental products — The Veterinary Oral Health Council (VOHC) maintains a list of products that are proven safe and effective, or your veterinarian can recommend a product they feel will work best for your pet. These products are designed to reduce plaque, tartar, and bacteria in the mouth.
  • Toothbrushing — The best way to prevent dental disease is once-daily toothbrushing, which may seem intimidating at first, but your cat may surprise you. Try this protocol to slowly introduce toothbrushing to your cat, but if you feel brushing would endanger you or be too stressful for your cat, you can try other products. 

Dental issues are common in cats and can cause them a great deal of pain and affect their quality of life. An annual or biannual veterinary visit is the best way to detect dental disease early when treatment is most effective. Contact our Colony Veterinary Hospital team if your cat is due for an annual examination or if you have seen signs of dental disease.