Feline odontoclastic resorptive lesions (FORLs) is a disease in cats characterized by resorption of the tooth by odontoclasts, cells similar to osteoclasts. A FORL is also known as a neck lesion, cervical neck lesion, cervical line erosion, feline caries, or feline cavity. It is one of the most common disease of domestic cats, affecting up to two-thirds. FORLs have been seen more recently in the history of feline medicine due to the advancing ages of cats, but 800 year old cat skeletons have shown evidence of this disease. Purebred cats, especially Siamese and Persians, may be more susceptible.