Infections of the 4th Premolar (Carnassial Tooth) in Dogs

When there is a break in a tooth, the inside pulp that contains blood vessels and nerve endings become exposed to the bacteria in the mouth. This infection is the most common cause of an abscess, which progresses into further infection and swelling of the mouth and face, tooth death, tooth root resorption, tooth loss, gum and surrounding tooth damage, and sinus tract drainage. Left untreated, a tooth infection quickly becomes a source of chronic pain, and may begin to affect your dog’s eating habits.

The two 4th premolars in dogs are called the carnassial teeth, or shearing teeth, and are used for breaking up or crushing hard material, such as bones or large pieces of meat. Often, a tooth can become broken, fractured, or cracked, which leads to an infection. If left untreated, this infection can lead to pain, swelling and periodontal disease. Once you see a broken tooth, or any associated symptoms, taking quick medical action can relieve pain and infection, and may prevent any secondary disease, and save the tooth.

Dogs often hide the pain of a tooth infection, and may not show any signs. Some symptoms you may notice are:

• Facial swelling
• Eye discharge
• Gum or tooth discharge
• Mouth swelling
• Pink or red bumps along the gum line
• Fatigue
• Signs of pain in or around the mouth
• Excessive drooling
• Lack of appetite
• Inability to eat
• Weight loss
• Favoring one side of mouth
• Bleeding from the mouth
• Change of attitude

An infection in the carnassial tooth is caused by the exposure of the delicate nerves and tissues inside the tooth to bacteria. This occurs by:

• Injury
• Chewing on hard items, such as bones, antlers, stones, ice cubes, hard plastic toys, cow hooves, cage bars, metal collars, or fences
• Attrition, or tooth to tooth contact that wears away teeth
• Periodontal disease
• Leftover tooth piece from a previous extraction
• Bacterial infection through the bloodstream

Due to the fact that dogs often hide their discomfort, your dog’s tooth infection may go unnoticed for some time, and may only be found during a routine exam. Other times, symptoms can be confused with those of an insect bite, an eye infection, or a puncture wound. If a tooth infection is suspected, your veterinarian will perform an oral and facial exam. A full mouth dental X-ray is taken to assess which tooth is infected, if the infection has spread, and the extent of any related tissue damage. Based on these findings, your veterinarian will discuss with you what treatments are available.

Once the infection has been confirmed, antibiotics may be prescribed, as well as anti-inflammatory and pain relieving drugs. Antibiotics may resolve the symptoms temporarily, but are usually not enough to get rid of the infection. The next step in treatment could include a root canal, vital pulp therapy, a bonded composite restoration, a crown restoration, or an extraction of the infected tooth. Your veterinarian will discuss with you the right option based on the severity of the infection, and the state of the tooth and its surrounding tissues.

Root canal

A root canal involves removing the infected pulp tissue inside the tooth. The space is filled, and a tooth colored restoration seals the space. This procedure allows the tooth to be saved, depending on the condition of the tooth and surrounding tissues

Vital pulp therapy

Vital pulp therapy intends to maintain the pulp tissue and protect it from bacterial invasion. It is often used in immature teeth, and involves strengthening the tooth from the inside. This procedure has a higher risk of failure than a root canal, and often needs the latter if the pulp therapy fails.

Bonded composite restoration

A bonded composite restoration is an organic resin that matches the strength and color of your dog’s own teeth. This resin is bonded to the tooth, filling in cracks and defects, and then polished.

Crown restoration

A crown restoration places a crown or cap over the top of the damaged or repaired tooth, and often follows a root canal treatment.

Extraction

While it is always preferred to salvage the teeth, circumstances, such as finances or the extent of the tooth and mouth damage, may not allow it. In these cases, an extraction may be recommended.  After the extraction, antibiotics and pain medications may be prescribed.

After any oral surgery, your dog may or may not need a diet change while the gums are healing. You may be told to feed only soft foods for the week following surgery. You may also be given antibiotics and pain medications to administer at home. A follow up exam is often scheduled for 6 months after any treatment. 

Prevent tooth infections by preventing your dog from chewing hard objects, schedule routine dental exams, maintain your dog’s teeth at home, and take care of any tooth damage as it occurs.