Feline resorptive lesions, also called odontoclastic resorptive lesions, are similar to cavities. These lesions are erosions of the tooth and occur at or near the cementoenamel junction, at the base of the tooth. The cause of the lesions is unknown but research has shown that these lesions are not cavities, which are very rare in cats.
Resorptive lesions are quite common in cats, with reports as high as 67 percent of felines being afflicted. The most commonly affected breeds are the Siamese, Abyssinian and Persian.
As with many ailments, the incidence of resorptive lesions tends to increase as the cat ages. These lesions are most often found on the labial and buccal surfaces of the molars and premolars.
Though many mild resorptive lesions go unnoticed, more advanced erosions can cause signs of illness.
What to Watch For Oral pain
Lack of appetite
Change in eating behavior
Change in food preference (from dry to soft)
An oral examination is usually all that is needed to detect resorptive lesions. However, sometimes excessive gingival tissue will grow and cover the lesion, making definitive diagnosis difficult. In addition to excessive gum tissue growth, advanced cases may result in extensive tooth destruction. Part of the tooth crown may be lost, or the tooth may even be completely lost with only root fragments remaining.
Feline resorptive lesions are placed into one of four stages. These stages can help guide treatment.
Stage one. This stage can be diagnosed using a dental explorer. These early lesions are small and involve the enamel and tooth cementum only. There is typically no pain associated and many cats show no signs of discomfort.
Stage two. At this stage, the lesions begin to cause discomfort and pain. The lesions involve the dentin but not the pulp. Dental X-rays are recommended to determine if the pulp is involved, in order to stage the lesions.
Stage three. At this point, the tooth structure is compromised. The lesions have extended into the pulp and dental X-rays are needed to determine the amount of pulp involvement.
Stage four. This is the most advanced stage of resorptive lesion and indicates chronic erosions with extensive tooth involvement. The roots may be completely altered by the process of erosion. The crown may be missing and gum tissue may have covered the remaining tooth remnants. Dental X-rays are necessary to identify root fragments.
The goal of treatment is to resolve tooth and mouth pain and attempt to restore a healthy mouth.
For stage one lesions, the treatment is a dental cleaning and polishing. These lesions are too small for restoration. A fluoride gel may be regularly applied to slow plaque accumulation.
For all other stages, removal of the tooth is the preferred treatment.
Home Care and Prevention
Once diagnosed, home care depends on the stage of tooth decay. For stage one lesions, tooth brushing and a fluoride gel can help slow progress of the erosions.
If the tooth was extracted, the cat should be fed a soft diet for a few days until the tooth socket has healed.
Since the cause of feline resorptive lesions is unknown, there are no preventive measures. Periodic oral examinations will help find lesions early. Regular tooth brushing and fluoride gels may help by removing plaque.