Tooth Root Abscesses

Laurie Anne Walden, DVM

Tooth root abscesses are painful and need prompt treatment, but the signs can be easy to miss. Dogs don’t always show that their mouths hurt, and tooth abscesses can mimic other conditions.
 
Causes
Tooth root abscesses are pockets of pus caused by bacteria that invade the deep structures of the tooth. They often occur in teeth with severe periodontal disease or gingivitis (gum disease), especially if the gum has receded around the tooth.
 
Teeth that are cracked or fractured are also at risk for root abscesses. Teeth can fracture when a dog chews on something hard, like a bone, cow hoof, ice cube, hard nylon toy, or rock. Fractures that expose the pulp cavity (the inner part of the tooth) give bacteria a route to the tooth root.
 
Affected teeth
The upper fourth premolar—the large cheek tooth on each side of the upper jaw—is a common site of root abscess. This tooth, also called the carnassial tooth, is used to crush food. When a dog crunches something hard, a carnassial tooth can sustain a slab fracture (shearing off a slab from the side of the tooth) or can crack down the center. The roots of the carnassial tooth reach nearly to the eye, so an abscessed root causes swelling just below the eye.
 
Root abscesses can occur in any tooth. The large canine (fang) teeth are frequently broken and are also common sites of root abscesses.
 
Symptoms
Although tooth root abscesses are very painful, dogs’ signs of mouth pain can be subtle. Some dogs don’t show any symptoms at all. Signs of a tooth root abscess can include the following:

• Bad breath (usually worse than typical “doggie breath”)
• Pawing at the mouth
• Rubbing the face on the ground
• Reluctance to eat or to chew on toys
• Chewing on only 1 side of the mouth
• Lump on the face just below the eye
• Draining wound on the face
• Jaw swelling

 
A veterinarian may be able to find evidence of a tooth root abscess during examination of an awake patient. However, dogs with tooth root abscesses sometimes have too much mouth pain to allow much of an oral examination without sedation.
 
Diagnosis often requires dental radiographs (x-ray images) or at least a full oral examination with the patient under anesthesia. Dental radiographs sometimes reveal tooth root abscesses that can’t be seen any other way.
 
Treatment
Untreated tooth root abscesses cause prolonged pain and tooth loss. The infection can spread to other tooth roots and to the face, potentially even affecting the eye.
 
Dogs with tooth root abscesses need antibiotics and pain relief. The source of the infection must also be removed. There are 2 options for treating an abscessed tooth root:

• Tooth extraction
• Root canal therapy, which lets the dog keep the tooth

 
If you think your dog might have a tooth root abscess, make an appointment with your veterinarian as soon as possible. Your veterinarian will examine your dog and, if the signs indicate an abscess, will probably prescribe an antibiotic and an analgesic (pain reliever).
 
The next step will be either another appointment with your veterinarian for tooth extraction or referral to a dental specialist for possible root canal therapy. Both extraction and root canal therapy require general anesthesia.
 
If you would like your dog to keep his tooth, root canal treatment is the best option. Antibiotics alone are rarely enough to treat a root abscess. However, not all teeth are candidates for root canal therapy. The dental specialist will evaluate dental radiographs to see if root canal treatment is a good option and will extract the tooth if necessary.
 
Prevention
Sometimes tooth root abscesses are unavoidable. But you can take some measures to reduce your dog’s risk:

• Maintain good oral hygiene: brush your dog’s teeth regularly, have your veterinarian examine your dog’s teeth at least once a year, and have the teeth cleaned as advised by your veterinarian.
• Don’t give your dog hard toys, ice cubes, bones, or other hard objects that could fracture the teeth.