By Karla S. Rugh, DVM, Ph.D.
Posted: December 19, 2012, 8 p.m. EST
Rabbit Cloud/Courtesy Kristen Boyle & Ryan Wilson
A rabbit's diet must include high-fiber foods to help keep its teeth worn down and prevent malocclusion.
Rabbits don’t have a lot of teeth (28 to be exact), but their choppers are essential and efficient tools that start the digestive process rolling from the very first bite. Adult rabbits have six incisors: four on the top and two on the bottom. One pair of upper incisors is small (peg teeth) and lies directly behind the front pair. Incisors are used for gnawing and biting off pieces of food. The premolars and molars (cheek teeth) are difficult to see without special instruments. These teeth are used to crush and grind food.
Rabbit teeth lack true roots and grow continuously — 4 or more inches per year! The teeth wear down naturally when the rabbit eats tough fibrous plant material. If the rabbit doesn’t get enough chewing exercise, the teeth can become overgrown and cause malocclusion, which is failure of the upper and lower teeth to meet properly. Some rabbits are predisposed to malocclusion because an inherited malformation of the lower jaw prevents the teeth from meeting properly.
If your rabbit develops incisor malocclusion, it may have difficulty eating and may be unable to completely open or close its mouth. Upon closer inspection, you’ll probably see the overgrown incisors. In extreme cases, the teeth protrude and twist as they grow, sometimes penetrating the soft tissues of the opposite jaw or, in the case of the lower incisors, the nostrils.
Cheek tooth malocclusion, which often accompanies incisor malocclusion, leads to the development of sharp points on the edges of the teeth. The points cut into the soft tissues of the cheeks and tongue and give rise to the signs of cheek tooth malocclusion: drooling, tooth-grinding and reluctance to eat.
Both types of malocclusion are treated by trimming the overgrown teeth, a procedure best performed by a veterinarian. Your rabbit will most likely tolerate incisor trimming while manually restrained; sedation or general anesthesia is necessary for cheek tooth trimming.
To prevent malocclusion, give your rabbit plenty of vigorous chewing exercise by feeding it high-fiber foods such as grass hay and fresh green veggies. A branch of apple wood placed in your rabbit’s cage makes a fun “chew-toy” that will satisfy your furry friend’s urge to gnaw. Diet alone may not prevent all cases of malocclusion; if your rabbit is predisposed to malocclusion because of a malformed lower jaw, you’ll probably need to have a veterinarian trim its teeth periodically.
Excerpt from the Popular Critters® Series magabook Rabbits®,with permission from its publisher BowTie magazines, a division of BowTie Inc. Purchase Rabbits here.