Tooth Resorption in Dogs

By Lorraine Hiscox DVM FAVD Dip. AVDC; Jan Bellows, DVM, Dipl. AVDC, ABVP

What is tooth resorption?

There is more than one type of tooth resorption. Tooth resorption is typically categorized as either internal or external with subcategories of each. Regardless of the type, tooth resorption is a common oral abnormality seen in dogs. Although the premolars of the lower jaw are most commonly affected, lesions can affect any tooth.

Tooth resorption is not typically observed with the naked eye; it is most often observed on radiograph (X-ray) examination. In fact, a study of 224 dogs, presented at a university dental service for oral care, found that more than half of the dogs (53%) showed radiographic evidence of tooth resorption.

"Tooth resorption is not typically observed with the naked eye; it is most often observed on radiograph (X-ray) examination."

In cases of internal tooth resorption, the root canal system will show an enlarged area with smooth and clearly defined margins. The recognition and treatment of external and internal tooth resorption in dogs is important for overall health and comfort.


What causes tooth resorption, where does it start, and how does it progress?

The exact cause is unknown.Despite many studies, there is no know link to diet, vaccines, or other diseases. Whatever the underlying cause, the end result is erosion of cementum and dentin that often progresses into the pulp of the affected tooth. Tooth resorption is considered painful once the lesion affects the crown, such that defects created in the crown permit oral bacteria to enter into the tooth.

How do I know if my dog has tooth resorption?

In most cases, tooth resorption does not have outward signs. Once the sensitive dentin is exposed, tooth resorption is painful and often manifests as muscular spasms or trembling of the jaw whenever the lesion is touched. Dogs with tooth resorption may show increased salivation, oral bleeding, or difficulty eating. There may also be fractured teeth due to a loss of structure of the crown.

How is tooth resorption treated?

Tooth resorption is believed to be progressive and can present itself in many stages. Once the resorption has eroded the tooth crown, or if there is significant root resorption such that the stability of the tooth is in question, then extraction of the tooth is necessary.

Your veterinarian will outline a treatment plan that will minimize pain and suffering for your dog. Treatment options include:

  • Watchful waiting. When the lesions are early and the tooth crown is not affected, your veterinarian may recommend regular follow-up. Follow-up visits determine if/when some form of intervention is required.
  • Extraction. When the tooth resorption has extended into the oral cavity, causing painful inflammation within the tooth crown, your veterinarian will recommend removing the affected tooth (teeth).
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