Dental caries (“decay”) are bacterial infections of the teeth. They are very common in people but uncommon in dogs and extremely rare or nonexistent in cats. This may be related to the fact that the saliva of dogs and cats is more alkaline than that of people, and the initial lesion of caries is acid demineralization of the enamel. Other factors may also play a role, such as differences in oral flora and diets that have fewer readily fermentable carbohydrates.

In dogs, decay usually occurs on the occlusal surfaces of molar teeth. It has the appearance of a brown cavitated lesion with a soft surface into which a sharp explorer tip can penetrate and “stick.”

The carious tooth structure must be removed using a caries curette or a dental bur. A radiograph should be taken to determine whether the infection has spread to the pulp, in which case the tooth also requires root canal treatment. The missing tooth structure is then restored using either amalgam or a bonded composite resin restoration.

Dogs that have dental caries are predisposed to additional lesions; treatment with a topical stannous fluoride product every 2 wk may help prevent caries in these animals. Because dogs do not expectorate, they swallow any medications used. Therefore, only small amounts should be placed on the occlusal surfaces of the teeth. Fluoride can cause gastritis, and it can be nephrotoxic if significant amounts are ingested.

Last full review/revision March 2012 by Jack Easley, DVM, MS, DABVP (Equine); Gregg A. DuPont, DVM, Fellow AVD, DAVDC