Cats do not develop the same type of cavities that people get. Cats do get holes in their teeth, but they are generally the same color as the tooth and are the result of tooth resorption rather than decay. Most commonly seen at or below the gumline, these "cat cavities" or "neck lesions" are now termed FORLs or feline odontoclastic resorption lesions. FORLs are very painful and often lead to shearing off of the teeth at the gumline. Difficulty eating, salivation, and tooth loss are some signs of "cat cavities", but sometimes no symptoms are noted.
Though they have been a recognized disease entity in both domestic and wild cats since the 1920s, it seems that since the late 1960s the number of cats affected by these lesions has skyrocketed. Research continues into the exact cause of FORLs, but overactive osteoclasts (odontoclasts) or bone resorption cells are seen in tissue samples consistently. Some factors that have been suggested as possible contributors to the risk of focal tooth resorption problems include:
- Inflammation around the teeth (gingivitis, periodontal disease, tartar)
- Resorption of the supporting ligaments of the tooth (deterioration of the periodontal ligaments without signs of inflammation)
- Diet (magnesium levels, acidifying effect)
- Indoor lifestyle, especially urban, and an urban water supply
- Tooth stress resulting from tooth malocclusion and abrasion
- Chronic virus diseases (especially Feline Immunodeficiency Virus)
Causes of FORLs
The exact cause of FORLs is still under investigation.
Approximately one-third of all cats will develop "cat cavities" over their lifetime. One study of a healthy cat population indicated the prevalence of these tooth problems in almost 50% of cats provided with a thorough dental and oral X-ray examination. Older cats are more likely to get FORLs and the lower premolar teeth are most commonly affected.
Extraction of affected teeth is usually recommended since studies on the restoration of diseased teeth indicate that over three quarters of restored teeth undergo deterioration. Preventive measures include regular tooth brushing at home, and perhaps feeding non-acidifying diets with higher magnesium, potassium, calcium and phosphorus content.