Dental Disease in Rabbits
Dr. Natalie Antinoff
Rabbits have a total of 28 teeth. This may be surprising, as many people do not realize that rabbits even have teeth other than the incisors (front teeth). Their teeth are different than ours in several ways; the most significant is that they are open-rooted teeth that grow continuously throughout their life. The grinding of the upper and lower teeth against each other is what keeps them from growing too long, so normal teeth have pretty much the same appearance to us. There is no enamel on the teeth, which lets them wear down more quickly than human teeth. The nerves do not travel the length of the tooth; rather, they stop just beyond the gumline. This prevents any discomfort to the rabbit in the portion of the tooth that is being normally worn down. Incisor malocclusion usually occurs because the lower teeth protrude in front of the upper teeth. The lower teeth then grow very long outside of the mouth, and the upper teeth curve backwards into the mouth. This is usually easy for you, the owner, to see.
Rabbits have six incisor teeth. There are four upper incisors and two lower incisors. In normal rabbits, both lower incisors and the front two upper incisor teeth can be seen by separating the front lips. The remaining two upper incisors are very small teeth which sit behind the first upper incisors. These small teeth are called "peg teeth." This feature is the main characteristic that differentiates rabbits from rodents. (You can probably see these peg teeth if you have a good rabbit who lets you handle his mouth.) When resting, the lower incisor teeth sit in the groove between the two sets of upper incisor teeth
The remaining teeth in the mouth are premolars and molars. These are also open-rooted teeth. Rabbits have three upper and two lower premolar teeth, and three upper and three lower molar teeth. There is very little difference in the appearance of the premolars and molars. All these teeth are referred to as the "cheek teeth." These teeth are located much further back in the mouth. There is a large space between the incisor teeth and the cheek teeth. (You will not be able to see these teeth in your rabbit, but you may be able to feel them.)
The most common problems of the mouth are related to malocclusion, or improper alignment, of the teeth. When the teeth do not meet properly, they do not wear down evenly, and the result is overgrowth of the teeth. This can occur with any of the teeth.
Molar malocclusion can occur along with incisor malocclusion or can occur by itself. One molar tooth may shift out of alignment, or the entire row of teeth may shift or meet improperly. When long, the upper cheek teeth typically grow towards the cheek, and the lower cheek teeth grow in toward the tongue. The uneven wearing results in sharp projections on parts of the teeth, known as points. These points can eventually cut the cheek or tongue, and not only cause pain and discomfort, but also provide a route for infection in the mouth.
Other diseases that can have a similar appearance include gastric stasis, tooth root abscess, kidney disease, bladder stones or any illness that causes discomfort.
Gastric stasis is the slowing down or stopping of the stomach and intestines, leading to discomfort. Rabbits may have decreased or no appetite and may grind their teeth.
Tooth root abscess or abscess anywhere in the face or head can cause discomfort, difficulty eating, grinding of the teeth and difficulty eating harder foods.
Bladder stones can cause discomfort and may lead to grinding of the teeth.
Grinding of the teeth can be a sign of general discomfort anywhere, and may not be related to the teeth.
Kidney disease or any other organ disease or infection can cause loss of appetite.