Tooth Root Abscess in Cats

Abscessed root of a lower canine toothWhat is a tooth root abscess?

A tooth root abscess is a severe infection that develops around the root of a tooth usually occurring from a broken or traumatized tooth.

What causes a tooth root abscess?

A tooth root abscess forms when bacteria enter the exposed root canal of the tooth. In cats, this most often occurs when the tooth breaks and exposes the tissues that lay beneath the enamel. A tooth root abscess may also develop in association with periodontal disease, an infection of the tissues surrounding the tooth.

"The most common cause of a broken
or cracked tooth
is traumatic injury."

What is the most common location for a tooth root abscess in cats?

Any tooth can fracture, however the large upper and lower canine teeth, followed by the upper fourth premolar, are the most commonly broken teeth that develop a tooth root abscess. These are known as the carnassial or shearing teeth, so this type of abscess is aptly referred to as a carnassial tooth abscess.

When either or both of the carnassial teeth are fractured exposing the underlying pulp a severe painful infection can develop.

 Slab fracture of the left upper fourth

A slab fracture develops when a cat’s cheek teeth bite down on a hard object at just the right angle and with just the right force to break off a flake or slab of the tooth, exposing the underlying sensitive dentin and often the nerve. The slab that breaks off may be a small chip or a large piece of the tooth.

Are there any obvious symptoms when a cat has a tooth root abscess?

Although humans know that abscessed teeth are very painful, cats do not typically show any obvious signs of pain when they have a tooth root abscess. Instead, your cat may be reluctant to chew on her toys or she might pull away when her head is touched. An observant owner may notice that their cat is only eating or chewing on one side of her mouth, or the cat drops her food when chewing on the affected side.

Some cats will also have bad breath while others may paw at the affected side of their face or rub their face along the ground. Pet owners may assume the cat simply has an itch, but it could be the sign of an abscessed tooth.

If the abscessed tooth is the upper fourth premolar or first molar tooth, the outward signs are often mistaken for some other problems, such as an eye infection or a puncture wound. This happens because these tooth roots lie just below the eye, and when they become abscessed the infection quickly spreads to the surrounding tissues. The tissue below the eye will usually become swollen and inflamed just before the abscess bursts. If you look inside the cat's mouth, there will often be swelling and redness on the gums around the affected tooth.

How is a tooth root abscess diagnosed?

In some cases, such as when there is an obvious slab fracture or damage to a tooth that is accompanied by the presence of a discharge, the diagnosis of a tooth root abscess is simple and straightforward.  Your veterinarian will need to take dental x-rays or refer you to a veterinarian that can determine whether the abscess has spread to the surrounding teeth, compromising their health.

What is the treatment for a tooth root abscess?

A tooth root abscess is a very painful condition and needs to be treated as soon as possible. Antibiotics will be prescribed to control the infection and either an anti-inflammatory and/or pain relief medication will be prescribed to help with soreness. Although this medical treatment will deal with the symptoms, it will not treat the underlying tooth injury.

There are two options for treatment of the abscessed tooth. One option is a root canal treatment, which usually saves the tooth, and the other option is extraction.

The tooth may be saved if a root canal treatment is performed. However, the likelihood that a root canal treatment of an abscessed tooth will be successful depends on the health of the surrounding tissues and the condition of the affected tooth. Some general practitioners are comfortable performing a root canal treatment on an abscessed tooth, but most veterinarians will refer these complex cases to a veterinary dental specialist ( 

     Fractured lower canine with nerve exposure    Root canal therapy to save the tooth

 Restored saved toothIf the abscessed tooth has extensive bone loss around its socket, or if there is significant damage to the crown of the tooth, your veterinarian may recommend extraction as the best treatment. Your veterinarian will be in the best position to recommend the appropriate option for your cat, depending on the severity of the abscess and the degree of damage to the tooth and surrounding structures.

If the abscessed tooth is extracted, your veterinarian will prescribe antibiotics and pain medications for a period of time, determined by the severity of the condition. Your cats may or may not require a change in diet during the post-operative recovery period. Once the gums have healed over, most cats can resume their regular diet and activity level.

All cats should have a dental examination performed by their veterinarian at least every six months. For a cat that has developed a tooth root abscess, your veterinarian may recommend more frequent dental examinations.


This client information sheet is based on material written by: Jan Bellows, DVM, Dipl. AVDC, ABVP

© Copyright 2013 LifeLearn Inc. Used and/or modified with permission under license.

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