Feline Odontoclastic Resorptive Lesions (FORLs)

What is a FORL?

The letters FORL stand for Feline Odontoclastic Resorptive Lesion. Other names for this disease include Neck Lesions or just Resorptive Lesions. We also sometimes call them “kitty cavities,” although they are not really cavities like humans get. Human cavities are the result of bacterial enzymes and acids digesting the teeth. However, FORLs are the result of the cat’s own body resorbing the teeth.

Why did my cat develop a FORL?

Unfortunately no one knows why FORLs develop. It is an area of ongoing research and we certainly hope to have an answer one day!

Are FORLs painful? My cat doesn’t seem to be in any pain!

Yes! FORLs are extremely painful! They may cause your cat to eat less, use one side of the mouth more frequently, or may even cause jaw chattering (hitting a nerve). Cats are masters at hiding their pain, so you may not see any of these signs at all – they may even continue to chomp away on dry food! However, these lesions are painful and must be treated.

How are FORLs diagnosed and treated?

We can often identify FORLs during our physical exam when we look inside the mouth. However, we also often diagnose FORLs during a dental cleaning, based on probing of the teeth and x-rays. By the time most FORLs are detected it is too late to save the tooth and the only option is extraction. Even if an early-stage FORL were detected and had a “filling” placed, it would eventually need extraction anyway.

What happens if we leave the FORL alone?

In addition to continued pain, bacteria in the mouth can invade the pulp chamber and an abscess can develop. An abscess (tooth infection) can lead to other infections in the body, such as on the heart valves.

How can we prevent future FORLs from occurring?

Keeping your cat’s teeth clean with as-needed dental cleanings and “home-care” (such as brushing his/her teeth and/or using other plaque reducing products) is the best way to promote good dental health, although there are no specific ways to prevent FORLs completely.

What is involved in a “Dental Cleaning” at Cat Care Clinic?

After running pre-anesthetic bloodwork, your cat will be anesthetized and his/her teeth will be cleaned similar to your experience at the dentist (removal of tartar, followed by polishing). Next, full-mouth x-rays will be taken so that your veterinarian can see what’s happening below the gum line and look for other diseased areas. She will then exam all the teeth and decide on a treatment plan. If extractions are required, your veterinarian will perform them. In addition to local anesthetic blocks in the mouth, your cat will receive multiple other pain medications, including medicine to go home.