Keeping Canine Teeth Healthy: What is a “Carnasial” Tooth Abscess?
The “carnasial” tooth or more correctly the upper fourth premolar is one of the primary chewing teeth of carnivores. It functions as a shearing tooth to shred food and is the largest tooth in your dog’s mouth. It is a somewhat flattened tooth in the upper jaw (maxilla) just below the eye. Because this is a major tooth that is important in chewing (its role being slicing and grinding food being chewed) it is somewhat prone to injury and secondary problems. This tooth frequently accumulates excessive tarter, perhaps, in part because of its proximity to the duct of the parotid salivary gland1.
The upper fourth premolar often demonstrates extensive gingivitis and gum retraction. To prevent this buildup it is necessary to practice good oral hygiene and to maintain good oral health through regular brushing of the teeth and regular preventive dental care by a veterinarian1. Click here to see a video about how to brush your dog's teeth.
The carnasial tooth is particularly prone to “slab fractures” and cracking that often allow exposure of the root canal and result in secondary infections. Slab fractures of this tooth should be treated aggressively. Oral radiographs should be a regular part of the dental examination to evaluate the roots of all teeth. Cracked or broken teeth should be evaluated for exposure of the pulp cavity. If the pulp cavity is open there is an increased risk of infection.
Anatomy of the carnasial tooth
The carnasial tooth has three distinct roots and each of them may be involved in an infection. Recent fractures may be sealed and capped but more long standing exposures may require a root canal. If infection is allowed to continue the root system will become infected and may ultimately cause an abscess formation. Carnasial tooth abscesses may open and drain between the tooth and the gum tissue but it is common for the abscess to involve the maxillary facial bone that overlies the tooth. The result will be an abscess that extends to the facial tissue just below the eye.
Clinical signs of tooth abscess in dogs
Abscessed teeth will commonly drain around the gum line but in the case of the carnasial tooth the roots are very close to the skin just below the eye. Gaurdians may often see a draining track just below the eye that discharges blood tinged fluid and pus. A complete oral examination may reveal chips or cracks of teeth.