Pus Cavity Forming Under Tooth in Dogs

PetMD Editorial
Written by:
PetMD Editorial
Published: July 2, 2008
Pus Cavity Forming Under Tooth in Dogs

Tooth Root (Apical) Abcess in Dogs

Similar to humans, dogs can experience apical abscesses, or pus formations that form under or in the tissues surrounding the dog's tooth. 

Abscesses occur for a variety of reasons, cause extreme pain, and can be treated with much success. If left untreated, however, bacteria can spead into other areas of the mouth, causing serious medical conditions.

Apical abscesses affect both dogs and cats. If you would like to learn how this condition affects cats, please visit this page in the PetMD health library.

Symptoms and Types

You may notice one or more of the following signs when a dog is suffering from an tooth root abscess:

  • Bad breath
  • Loose teeth
  • Facial swelling
  • A visibly broken tooth
  • A strongly discolored tooth
  • An inability to chew
  • Increased presence of plaque on teeth



Periodontal disease can cause the formation of an abscess, which is more common in dogs that have a tendency to bite or chew frequently (e.g., puppies that play and tug frequently). If left untreated, facial or mouth traumas, bacterial infections, and diabetes can all contribute to the formation of an abscess.


An oral and dental examination can identify if your dog has an abscess. Blood tests, on the other hand, can be used to determine if the abscess is caused by a more serious underlying medical condition.


It is common to drain the fluid under or surrounding the tooth; this helps to eliminate any any infection. In many cases, the tooth will be extracted to expedite the dog's recovery time. Cold packs and antibiotics will help to reduce the inflammation, and pain medication will be given to provide comfort during your pet's recovery.

Living and Management

During the follow-up exam (within 7 to 10 days of treatment) the veterinarian will test for sensitivity, check for healing at the site of the extracted tooth, and ensure there are no infections present. Infection is a common issue, so limit chewing, biting, and hard foods to help with the healing process.

Several behavioral changes can be made to hasten the cat's recover time, such as eliminating any hard bones or other chewable objects that may be too tough to bite on. Additionally, bring the dog in for regular oral exams to check for any tooth abnormalities.


Strong oral hygiene and maintenance can work to prevent the formation of abscesses in the dog's mouth. Limiting the amount of chewing on hard objects or pulling on the dog's teeth (through tugging) will also help reduce the likelihood of an abscess.

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