THE TOOTH FAIRY: DENTAL PROBLEMS IN RABBITS

By Janet Tast, D.V.M.

The Basic Bunny Mouth

Rabbits are differentiated from rodents by having a second set of teeth called peg teeth behind their top incisors ( the classic "bugs bunny" teeth.) Rabbits have a space behind the incisors called a diastema, which actually is quite handy when examining a mouth or giving oral medication. They have three upper premolars(each side) and three upper molars. The lower jaw ( mandible) has two. Rabbits save greatly on their dental bills by having open tooth roots which mean the teeth grow continually. The lower incisors rest in the groove between the two upper incisors, the enamel being thick in front and thinner behind helps to keep a sharp edge on the teeth. (all the better to shred carpet or other unacceptable fiber supplements) The molars or grinding teeth will wear down in parallel rows and move in almost a circular motion. This is easy to visualize watching a rabbit pull up grass and chew away. They do manage to look quite cute in the process too!

Open Wide- Common Dental Problems

Malocclusion of the incisors is a very common problem. This is usually an inherited trait where the lower jaw is longer and the incisors do not wear down properly. In wild rabbits this will prove fatal since the animal will eventually be unable to eat. Occasionally this malalignment can be due to an injury, malnutrition or infection of a tooth root. A minor defect may not manifest itself until the rabbit is older. Most owners will observe the rabbit having trouble picking up food or start to see the bottom incisors as they grow and grow!! There have been many horrifying case reports( mostly pathology reports) of rabbits with lower incisors almost touching their eyes or upper incisors that have grown into the roof of their mouth.!

Malocclusion of the molars can also occur secondary to the jaw malalignment. This can lead to "points" or sharp edges that will hurt or abrade the inside of a rabbit's mouth. Owners may see food falling out of the mouth, drooling or notice weight loss. A veterinary exam with an otoscope( instrument usually used to examine ears) can detect most tooth problems but not all. A rabbit's mouth is used for efficient grinding and hence does not open very wide. (just compare to a dog or cat or human). Add the factor of some less than cooperative patients and there can be difficulty in seeing all of the dental arcade or checking for infection.

Abscesses( a word well known in the rabbit veterinary world) can be the cause or effect of a malocclusion problem. Because the long roots or the incisors run under the eye and tear ducts, inflammation or infection can cause ocular(eye) problems, chronic infection discharge, etc.. But how to fix?

Treatment -Where is the Orthodontist???

Treatment for malocclusion depends on the severity. The first issue is that many rabbits presented to a veterinarian for dental disease can be chronically debilitated with weight loss and infection. Our first line of defense is to trim the teeth so food can be ingested easier and to "beef up" the rabbit. We evaluate diet, soften food, give medications and fluids if necessary. After reevaluating weight and condition, several medical options may be used.

Trimming the teeth is the most commonly performed procedure and is usually done with a hand held nail trimmer or similar instrument. This is far from ideal since splitting of the teeth or jagged edges may occur increasing the risk of infection. However, it has the distinct advantage of being performed quickly, without anesthesia, and can often be accomplished by some owners at home. ( a select and talented group) The second option of filing the teeth with a dental drill provides a smooth even surface but does require anesthesia. Since incisors grow out every six to eight weeks, trimming frequently can add to stress, risk of infection and cost.. When malocclusion is very severe or requires frequent trimming then surgical extraction is an option. Extraction is done under general anesthesia and all four incisors are removed plus the peg teeth. Commonly because the roots are long and the teeth weakened, the teeth can break requiring a repeat performance in six to eight weeks. Post operative care will depend on the individual rabbit. Pain medications and antibiotics are always given in the immediate post surgical period and may be continued at home if deemed necessary. Most rabbits do remarkably well and are eating softened or chopped food soon after surgery.

Molar malocclusion also requires general anesthesia. Because molar problems occur with higher frequency in our geriatric population, our choice of sedation is always a bit precarious. Radiographs(x rays) help in determining if there is an abcess or underlying bone infection to be addressed Filing molars is accomplished with a dental file or an instument called a ronguer. This is even more of a challange because of the small amount of room in a rabbits mouth. Let's see: rubber band or instument to hold mouth open, light to see, an intrument to file and one or two fingers, ends up feeling like a clown car at the circus... Unfortunately molars are very difficult to extract, and we are often limited to filing the sharp edges.

But At Least They Don't Get Cavities! Tooth Problems in Rabbits

THE TOOTH FAIRY: DENTAL PROBLEMS IN RABBITS

By Janet Tast, D.V.M.

The Basic Bunny Mouth

Rabbits are differentiated from rodents by having a second set of teeth called peg teeth behind their top incisors ( the classic "bugs bunny" teeth.) Rabbits have a space behind the incisors called a diastema, which actually is quite handy when examining a mouth or giving oral medication. They have three upper premolars(each side) and three upper molars. The lower jaw ( mandible) has two. Rabbits save greatly on their dental bills by having open tooth roots which mean the teeth grow continually. The lower incisors rest in the groove between the two upper incisors, the enamel being thick in front and thinner behind helps to keep a sharp edge on the teeth. (all the better to shred carpet or other unacceptable fiber supplements) The molars or grinding teeth will wear down in parallel rows and move in almost a circular motion. This is easy to visualize watching a rabbit pull up grass and chew away. They do manage to look quite cute in the process too!

Open Wide- Common Dental Problems

Malocclusion of the incisors is a very common problem. This is usually an inherited trait where the lower jaw is longer and the incisors do not wear down properly. In wild rabbits this will prove fatal since the animal will eventually be unable to eat. Occasionally this malalignment can be due to an injury, malnutrition or infection of a tooth root. A minor defect may not manifest itself until the rabbit is older. Most owners will observe the rabbit having trouble picking up food or start to see the bottom incisors as they grow and grow!! There have been many horrifying case reports( mostly pathology reports) of rabbits with lower incisors almost touching their eyes or upper incisors that have grown into the roof of their mouth.!

Malocclusion of the molars can also occur secondary to the jaw malalignment. This can lead to "points" or sharp edges that will hurt or abrade the inside of a rabbit's mouth. Owners may see food falling out of the mouth, drooling or notice weight loss. A veterinary exam with an otoscope( instrument usually used to examine ears) can detect most tooth problems but not all. A rabbit's mouth is used for efficient grinding and hence does not open very wide. (just compare to a dog or cat or human). Add the factor of some less than cooperative patients and there can be difficulty in seeing all of the dental arcade or checking for infection.

Abscesses( a word well known in the rabbit veterinary world) can be the cause or effect of a malocclusion problem. Because the long roots or the incisors run under the eye and tear ducts, inflammation or infection can cause ocular(eye) problems, chronic infection discharge, etc.. But how to fix?

Treatment -Where is the Orthodontist???

Treatment for malocclusion depends on the severity. The first issue is that many rabbits presented to a veterinarian for dental disease can be chronically debilitated with weight loss and infection. Our first line of defense is to trim the teeth so food can be ingested easier and to "beef up" the rabbit. We evaluate diet, soften food, give medications and fluids if necessary. After reevaluating weight and condition, several medical options may be used.

Trimming the teeth is the most commonly performed procedure and is usually done with a hand held nail trimmer or similar instrument. This is far from ideal since splitting of the teeth or jagged edges may occur increasing the risk of infection. However, it has the distinct advantage of being performed quickly, without anesthesia, and can often be accomplished by some owners at home. ( a select and talented group) The second option of filing the teeth with a dental drill provides a smooth even surface but does require anesthesia. Since incisors grow out every six to eight weeks, trimming frequently can add to stress, risk of infection and cost.. When malocclusion is very severe or requires frequent trimming then surgical extraction is an option. Extraction is done under general anesthesia and all four incisors are removed plus the peg teeth. Commonly because the roots are long and the teeth weakened, the teeth can break requiring a repeat performance in six to eight weeks. Post operative care will depend on the individual rabbit. Pain medications and antibiotics are always given in the immediate post surgical period and may be continued at home if deemed necessary. Most rabbits do remarkably well and are eating softened or chopped food soon after surgery.

Molar malocclusion also requires general anesthesia. Because molar problems occur with higher frequency in our geriatric population, our choice of sedation is always a bit precarious. Radiographs(x rays) help in determining if there is an abcess or underlying bone infection to be addressed Filing molars is accomplished with a dental file or an instument called a ronguer. This is even more of a challange because of the small amount of room in a rabbits mouth. Let's see: rubber band or instument to hold mouth open, light to see, an intrument to file and one or two fingers, ends up feeling like a clown car at the circus... Unfortunately molars are very difficult to extract, and we are often limited to filing the sharp edges.

But At Least They Don't Get Cavities!