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Dental Disease in Rabbits

Diseases and conditions related to the mouth and teeth are the most common veterinary problems seen in rabbits. Some may be preventable, and some may require occasional treatment, but some may be lifelong problems. When properly managed, however, many do not affect the quality or length of the rabbits’ lives.

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.

In the wild, rabbits eat mainly grasses and low-growing shrubbery. The incisor teeth function to crop or shear plant material, and then the cheek teeth are used to grind the material before swallowing. This is similar to humans, who bite with the teeth in the front of their mouths and chew with the molars. Unlike many other species, your rabbit’s teeth continually grow. The constant actions of cropping with the front teeth and chewing with the cheek teeth keep the teeth well aligned and provide constant and even wear on all the teeth, preventing overgrowth. The normal rabbit’s teeth, therefore, do not require trimming.

Malocclusion may begin in the incisor teeth (front teeth), the molar teeth (back teeth), or both. There are many predisposing factors, including heredity, diet and nutrition, injury to the tooth roots or face, and infection. When malocclusion is present, the teeth continue to grow without being properly worn by the opposing teeth. The incisors can curl and twist, leaving the rabbit unable to pick up food.

If malocclusion occurs in the molar teeth, they can develop “points,” sharp edges that result from the uneven wear of the teeth. These points can cut into the inner cheeks and tongue. This is not only very painful, but also can lead to infection in these areas.

What to Watch For

Diagnosis

Veterinary examination can usually identify incisor malocclusion. Your veterinarian may use an otoscope (the instrument usually used to look in the ears) or another type of speculum during the exam to look at the molar teeth. Sedation may be required for complete evaluation of the molar teeth. Additional tests may include:

Treatment

Treatment for malocclusion involves trimming (filing or clipping) of the teeth. The incisors can usually be trimmed without the use of anesthesia, although anesthesia is almost always necessary for trimming of the molar teeth.

Your veterinarian should clean any wounds inside the mouth when the teeth are trimmed. You may be instructed to flush or clean a particular area. Antibiotics may be prescribed if infection is suspected, but are not routinely necessary if there is no suspicion of infection.

In severe cases, the incisor teeth can be surgically removed. This is a permanent procedure and must be discussed with your veterinarian.

Home Care and Prevention

After a tooth trim, your rabbit may need soft food for one to three days while the mouth heals. Force-feeding or syringe feeding may be necessary.

Pets with a history of malocclusion are likely to need repeat tooth trimming. Some rabbits need veterinary attention only once or twice a year; others may need it as often as every six weeks. Most rabbits are somewhere in between these extremes.

Feeding your rabbit coarse hay for grinding of the back teeth can help promote normal wear of the teeth. Watch your rabbit’s eating habits closely so problems with the teeth can be addressed as soon as they start.

Feed your rabbit a good quality of rabbit pellet that is high in fiber. Fresh hay should be available at all times to encourage grinding of the back teeth. Stem hay is better than commercially packaged leaf or “hay cubes.”

Check your rabbit’s incisor teeth periodically. Ask your veterinarian to check the incisor and molar teeth any time your rabbit gets examined. The molars should be checked at least once a year, but preferably twice a year.

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.

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.

Veterinary examination can usually identify incisor malocclusion. Your veterinarian may use an otoscope (the instrument usually used to look in the ears) or another type of speculum during the exam to look at the molar teeth. Your rabbit may need to be held wrapped in a towel to permit this.

Sedation may be required for complete evaluation of the molar teeth. A rabbit’s mouth is very small, making it difficult to see all areas of the teeth in an awake patient. Subtle problems may not be seen without sedation.

Radiographs (x-rays) of the skull may be necessary to evaluate the tooth roots for infection, and to evaluate the nearby bones for signs of trauma or fractures. Sedation is required for diagnostic radiographs of the head region. (Even the most docile rabbits will not stay still enough for the proper positioning for the required views.)

If there is suspicion of infection, cultures will be necessary to identify the type of bacteria present, and to choose the best antibiotic to fight that infection.

Therapy

Treatment of malocclusion consists of the veterinarian trimming (sometimes called filing) the abnormal teeth. The incisor teeth can be trimmed without sedation in most rabbits. Sedation is required for proper trimming of the cheek teeth, and may even be necessary to completely evaluate the molar teeth. Although the procedure itself is painless in rabbits (the nerves do not extend to the ends of the tooth), it is impossible to open their mouths wide enough to trim the cheek teeth. The gums are often inflamed, and may bleed or may be nicked when trimming the teeth; however, these small areas usually heal very quickly once the inciting tooth is removed.

Treatment for malocclusion involves trimming (“filing” or “clipping”) of the teeth. Although this will not eliminate the problem, it will return the teeth to a normal length so that the rabbit can eat properly, and will remove all the points which may be cutting into the gums.

The incisors can usually be trimmed without the use of anesthesia in most rabbits, but sedation may be used for your rabbit if it is particularly nervous or sensitive.

Anesthesia is almost always necessary for trimming of the molar teeth. The mouth of a rabbit is very small and narrow and can only open a small distance, even under anesthesia. This is a bit like working in a deep hole, and in order to get the instruments into the mouth, rabbits need to be sedated.

The sedation that usually works best is injectable sedation (shots given in the vein or muscle), which lets the veterinarian work in the mouth without the presence of a facemask (which would be required with gas anesthesia). The disadvantage is that rabbits wake up more slowly from the injectable anesthesias.

Any wounds inside the mouth should be cleaned by your veterinarian when the teeth are trimmed. You may be instructed to flush or clean a particular area inside the mouth at home if there is a severe wound, but most heal very quickly without treatment.

Antibiotics may be prescribed if infection is suspected, but are not routinely necessary if there is no suspicion of infection. Your veterinarian will probably start an antibiotic based on what is effective against common bacteria of the mouth, but may change that if the bacterial cultures show that a different antibiotic may be better.

In severe cases, the incisor teeth can be surgically removed. This is a permanent procedure that must be discussed with your veterinarian on an individual basis. Many veterinarians will refer patients for this procedure.

Most rabbits, once diagnosed, will require periodic trimming of the teeth for life, since the malocclusions can’t really be corrected. The frequency of trimming varies with the individual rabbit and the severity of the abnormalities. Some may only be once or twice a year; others may be every two to three months.

Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve.