Dental Disease
Dental disease in rabbits is a very commonly diagnosed problem and is now recognized
as the underlying cause of numerous other disorders. For this reason an understanding
of dental health and physiology are crucial for veterinarians that treat rabbits and for
rabbit owners alike.
Rabbits are herbivorous, naturally eating a wide variety of vegetation and roughage. A
unique feature of rabbits is that all of their teeth are open rooted which means that their
teeth grow continually throughout their life. A healthy rabbit eating a proper diet
constantly chewing will wear down the teeth as they grow.
Signs of dental disease
Signs of dental disease are very broad and may be non specific. Early signs can be
subtle and may not be immediately noticeable to the rabbit owner. The rabbit may
change its food preferences, stop eating certain things that may be difficult to chew, or
drop food from its mouth. The rabbit may have some weight loss or may look unkempt
from a change in grooming habits, especially if the incisors are overgrown. Advanced
signs of dental disease may be excessive salivation, loss of appetite, malodorous breath,
and severe weight loss. Also, the rabbit may present for another problem such as GI
stasis, an abscess, or an infected tear duct, all secondary to the primary dental disease.
Incisor Disease
Pictured left are Incisor
malocclusions. These
are the front teeth that
are easy to see in
rabbits. There are
actually 6 teeth in
these pictures. Four
incisors and two peg
teeth. Malocclusions
can happen for many
reasons including
infection, trauma, and
congenital defect.
Treatment starts with
monthly trimming with
a diamond burr and
treating any infection
associated with the
malocclusion. These
teeth should not be
trimmed with anything else besides the diamond burr. Some rabbits may qualify for
incisor removal. Your vet can help you decide which treatment is appropriate.
This rabbit had a traumatic
blow to the nose. The upper
incisor on the right fractured
below the gingiva. The
tooth continued to grow until
it erupted behind the end of
the fractured incisor that
was above the gingiva. The
the vestigial piece of tooth
was removed and this bunny
went back to normal
occlusion.
Causes of dental disease
Dental disease in rabbits is
most commonly caused by
dietary and genetic factors.
Genetic predisposition is very
common. With inbreeding,
some rabbits are born with
incisor malocclusion in which
the incisor teeth overgrow and
curl around because they do
not meet properly. Some
rabbits breeds prefer elongated
or shortened skulls (depending
on the breed type) which also
leads to dental occlusion
problems. Another common
cause is diet. Many rabbits are
primarily fed a diet of pellets.
Because the pelleted food is
dense in nutrient content and is already pulverized, the rabbit chews less. Rabbits’
molars curl as they continually grow. The lower molars develop points that grow into the
tongue and the upper molars develop points that grow out into the cheeks because of
decreased wear from less chewing. These changes occur gradually with time and can
lead to many secondary problems including abrupt loss of appetite and infections.
Acquired dental disease with deterioration of the tooth quality, malocclusion and
elongation of the roots with abscesses is another form of dental disease in rabbits. Diet,
genetics, and metabolic bone disease are all proposed causes for this problem.
Molar Disease
Molar disease is a very serious problem among our pet bunny population. Mildly affected
molars may be treated with a straight file as outpatients. For severely overgrown molars
or molars with points, a low speed dental drill with a straight dental bur can be used to
file down the molars and correctly reshape the teeth. Infections of the molar roots are
common in dental disease and often lead to the formation of abscesses and infection in
the surrounding bone. If an abscess is present, surgical treatment is required to remove
the entire abscess and the capsule. Involved bony tissue should be debrided. There are
many therapies we employ depending on the severity of the abscess.
Dental Abscess!!
Diagnosis
A dental exam should be a part of the annual physical examination. By lifting the lips to
check their length and occlusion, the incisors are checked. Also during the exam, the
veterinarian will check for the overall body condition, the coat condition, jaw swellings,
moisture from the mouth around the chin and neck, and moisture around the eyes,
which can all be indications of dental disease. The sides of the cheeks are palpated for
any sharp protrusions. We use a lighted nasal speculum to visually evaluate the molars.
Occasionally, we can not see points or spurs on the molars well and will recommend a
more complete dental exam and filing of the molars under anaesthesia based upon our
observations.
The dental examination under anaesthesia can be performed safely after we determine
that your rabbit is a safe anaesthetic risk. This may require blood work. The anaesthetic
agent used is usually isoflurane gaas. It is very safe and the rabbit recovers very quickly
when this gas is used. We may add analgesics (pain medicine) to decrease the stress of
the procedure and improve the rabbit’s recovery. Specialized instruments are utilized to
visualize the oral cavity including cheek spreaders, an incisor speculum, and a special
light source. Special diamond files, rongeurs, and straight dental burs on a low speed
drill are used to remove points and file the teeth down. A system for grading the extent
of dental disease based on radiographs has been developed. The extent of dental disease
present is graded I through V with V being most severely effected. While under
anaesthesia, we may take radiographs to evaluate the tooth roots and abscesses.
Pictured above is a tongue ulcer caused by a draining tooth root abscess at the back of
the mouth. This bunny was drooling excessively and had a foul odour from the mouth.
All the molars are abnormal in this picture.
Treatment is determined by the extent of the disease. We will present you with the
options once a thorough evaluation has been done. The first step is making an
appointment.
This bunnies abnormal smile is caused by an ear infection. The nerve that is close to the
base of the ear has become inflamed causing the cheek to tighten on one side (picture
side left). There is an abscess in the ear canal. This will lead to abnormalities in
chewing/eating which will lead to dental problems and cheek problems. So the original
problem (the ear abscess) must be treated first to help treat the dental and cheek
problems.