Oral Resorptive Lesions in Dogs

Key takeaways

Oral resorptive lesions in dogs occur when the hard tissues of the tooth root are destroyed by cells called odontoclasts, leaving a pocket in the tooth.

  • These lesions usually occur where the root and the crown meet, but can occur anywhere on the root
  • There are usually no outward signs until the pulp is exposed, at which point symptoms may include increased salivation, oral bleeding and difficulty eating
  • Most oral resorptive lesions are diagnosed by X-rays
  • Treatment, if needed at all, may involve extracting the tooth, amputating its crown, or root canal
  • As the disease is progressive, the prognosis for preserving the affected tooth is guarded
  • Prognosis is good following extraction or crown amputation
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A closer look: Oral Resorptive Lesions in Dogs

Oral resorptive lesions are uncommon in dogs and very common in cats; data from reporting in cats is presumed to apply to dogs. Since the cause of this disease process is not well understood, it is difficult to identify preventive measures.

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Risk factors

Oral resorptive lesions are uncommon in dogs. Before lesions reach the inner layers of a tooth, they are asymptomatic, but later-stage lesions are painful and require veterinary intervention. As a progressive disease, these lesions will not improve without treatment. There is also the potential for these lesions to become infected. Oral resorptive lesions are not life-threatening. In extreme cases, loss of appetite may be seen.

Possible causes

The cause of odontoclastic resorption in dogs and cats is not known. In cats, growing evidence suggests that these lesions do occur even in the absence of gingival or periodontal inflammation, so it seems likely that dental disease is not the culprit.

Main symptoms

In most cases, tooth resorption does not have outward signs until the erosion extends into the pulp cavity.

Testing and diagnosis

Most of the time, oral resorptive lesions are not diagnosed clinically, but rather by X-rays during an unrelated dental procedure under general anesthesia.

Steps to Recovery

The goal of treatment is to relieve pain or discomfort. One option is to leave the tooth and monitor for progression of the lesion. Another option is root canal therapy. Root canal is rarely indicated because the lesion may still progress. If the tooth roots are not yet resorbed, extraction of the entire affected tooth may be the best course of action. In cases where the tooth root is resorbed, amputation of the crown of the tooth only may be sufficient. Crown amputation may require regular X-rays to ensure the root is resorbing.

Prognosis with extraction and crown amputation is good, but guarded in the case of root canal therapy.

Prognosis with appropriate treatment and monitoring is good. Current data suggests that where one tooth is affected, other teeth are likely to become affected as well. Lifelong diligent monitoring is required once resorptive lesions are identified.


The cause is unknown, so no prevention is possible. Prognosis is not improved by conscientious dental hygiene. It is recommended that teeth are examined annually, including X-rays, to catch potential lesions early. There is no data to suggest that the condition is contagious.

Are Oral Resorptive Lesions in Dogs common?

Oral resorptive lesions are uncommon in dogs.

Typical Treatment

  • Conservative (monitoring of tooth)
  • Tooth extraction
  • Root canal therapy
  • Crown amputation
  • Pain management

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