by Sari Kanfer, DVM
Rabbits are herbivorous animals, which means that they have evolved over the eons to obtain nutrition from plants. Grasses, leaves and other plants are very tough, therefore rabbit teeth have to be very hard to break down the plant fibers. Similar to horses, rabbits in the wild have to graze many hours a day to obtain sufficient nutrients from plants. Because of this constant wear, rabbit teeth grow continuously throughout their entire life. When rabbits are fed a diet deficient in tough, fibrous plant matter (like hay, grass and vegetables), their teeth are not worn down properly. The individual teeth wear down at different rates, so the teeth cannot meet normally, and the teeth grow in an even more abnormal pattern. Malocclusion is the term for teeth that do not meet normally.
Some rabbits are born with bad teeth; either an underbite, an overbite, or other malformation. These rabbits need frequent dental care, and depending upon the problem, may never have a normal life. Other rabbits are born with normal teeth, but the do not develop normally. Occasionally, malocclusion can be caused by trauma, for example, being bitten on the head by a dog, or falling and breaking a tooth. But most frequently, malocclusions are the result of too little fiber in the diet.
Normal Rabbit Teeth
Whatever the initiating cause, tooth problems in rabbits usually present in one of the following manners:
1. Malocclusion and overgrowth of incisors
2. Sharp points on the inside edge of the lower cheek teeth, or outer edge of the upper
These points can injure the tongue, occasionally bad enough to cut the tongue in half! Upper cheek teeth points often cut the inside of the cheek, eventually causing an abscess.
3. Maloccluded teeth don’t get worn down properly and they continue to grow.
Unable to grow into the mouth and be worn down, the tooth root becomes elongated and grows deeper into the upper and lower jaw bones, causing a bone abscess.
4. The tooth roots of the upper teeth can press against the tear ducts and contribute to eye discharge.
Signs You May See
- NO SIGNS AT ALL!!!!
- Decreased appetite, weight loss
- Saliva or food build-up under chin, near lips, on the inside of the front legs
- Reluctance to eat hard food
- Stinky Breath
- Lump on the outer cheek, under the eye
- Lump under lower jaws (lumps start small, but can get very large)
- Discharge from cheek or chin/lower jaw area
- Incisors that are uneven (gently lift upper lip to check incisors). If uneven incisors are present, there is a very good chance that the cheek teeth are abnormal as well.
What Can Be Done If Your Bunny Has Malocclusion
X-rays are frequently needed to assess the extent of dental disease. Because of how rabbit mouths are formed, it is difficult to completely examine the entire mouth unless a rabbit is under anesthesia. Also, most malocclusions cannot be treated in an awake rabbit, therefore anesthesia is required. Pain control is another important part of treating malocclusions.
Under anesthesia, the veterinarian will trim and file off sharp points and abnormal tooth edges. If an infection or abscess is present, treatment is determined by location and severity. Sometimes oral antibiotics and wound flushing are sufficient, but frequently surgical treatment is indicated. Rabbit pus is very thick and the ideal treatment for rabbit abscesses is complete surgical removal. But some abscesses are too large and in too small of an area for complete removal, or involve extensive bone infection. Your veterinarian will discuss with you the proper treatment based upon how things look upon examination.
Dental problems and abscesses are definitely diseases that should be treated by a veterinarian who is experienced with rabbits. The key thing to remember is that your bunny will never be 100% normal, and will need rechecks and tooth trims for the rest of his/her life. Non-treatment of malocclusions only allows worsening of the condition, and further pain for your bunny.
Dr. Sari Kanfer practices at Exotic Animal Care Center in Pasadena, CA, and can be reached for appointments or consultations at (626) 405-1777. She joined the board of Zooh Corner as Medical Director in January of 2002.
Cat Logsdon has run Zooh Corner Rabbit Rescue since 1993 and has many years of practical experience. She may be reached via e-mail.