Rodents include the Chinchilla, Gerbil, Guinea Pig, Hamster and Rats
As stated above, teeth evaluation is
the basis for the differentiation between rabbits and rodents. Rodents
only have one set of incisor teeth and rabbits have the "peg teeth" as
the second set.
Guinea pigs and chinchillas have continually growing and eruption
incisors and cheek teeth as also occurs in the rabbit. This dentition
has been called elodont.
Hamsters, girbils, mice, rats and other small rodents have
continually growing and erupting incisors; however, their cheek teeth
are brachyodont. They have a short crown and a well defined root.
These brachyodont teeth do not grow continually.
Chinchillas: Kirby and his brother eating.
Dental formula for guinea pigs and chinchillas; 2(I2/1 C0/0 PM1/1 M3/3) = 20
The guinea pig and chinchillas have incisors and cheek teeth that continually grow.
Dental formula for the girbel, hamster, mice and rats is; 2(I2/1 C0/0 PM0/0 M3/3) = 16
The girbel, hamster, mice and rats have
continually growing incisors however the cheek teeth are not
continuously growing and are classified as short (hypsodont) teeth.
Additionally, some hamsters only have 12 teeth as they may have 2
molars (as opposed to 3) on the top and the bottom dental arches.
Dr. Kressin performing a brief facial evaluation.
As the incisors elongate, they tend to twist.
A speculum is used to get an initial overview.
Rodents have continuously growing teeth. The number of
teeth vary between species of rodents. The diet is fundamental to
dental and overall health for these animals. Continuous growing teeth
remain functional as a result of the normal wear from chewing feeds.
Every time a rodent stops eating, reduces feed intake or becomes
anorexic, the teeth may overgrow. The result is a painful mouth and in
some cases the inability to eat. This becomes a life threatening
problem very rapidly. Early presentation of rodents for a dental
evaluation may be life saving.
Sammy, a beautiful 9 month Guinea Pig
A routine radiograph to evaluate the occlusion.
A routine radiograph to evaluate for tooth root elongation. Tooth roots appear
normal in the radiograph above.
Chinchilla dropping feed and eating less than normal.
Chinchilla dental care
Dental radiograph shows uneven upper Dental radiograph from opposite side
dental arcades due to coronal elongation. consistently demonstrates coronal
Mandibular cheek teeth have unequal length disparity between left and right
coronal height creating a "wave" upper dental arcades. Kirby right view.
appearance. Kirby left lateral view
prior to operative dentistry!
Kirby after operative dentistry.
This was the initial occlusal adjustment
to reduce the "wave" occlusion. One large
spike was removed from lower right second
molar tooth. The teeth require periodic
Computed tomography (CT scan or Cat scan) was
suggestive of mandibular brachygnathism to the veterinary radiologist.
These chinchillas must be fed a diet that will maximize dental wear and
periodic professional occlusal adjustments will be required.
The owner reported rapid return to normal eating of a diet with long
stem hay. The large spur on the lingual aspect (tongue side) of the
lower right second molar was causing a deep laceration into the palate.
This resulted in pain and discomfort as well as an innefective dental
occlusion and abnormal tooth ware.
Kirby is back to eating hay! Kirby is eating and quite playful.
Rabbit & Rodent Dental Care
A comprehensive oral health assessment for rabbits
therefore must be performed under anesthesia. Assessments are made for
periodontal disease (radiographs and probing), tooth irregularities
(tooth spikes or waves of the dental arcades), tooth infection (dental
abscesses) soft tissue injuries or for oral tumors.
The veterinarian may need to provide occlusal adjustments (grinding
teeth down) to imporve the occlusal relationships between the upper and
lower dental arcades (arches). Endodontic (vital pulpotomy)
therapy can be used to save tooth that are fractured and have pulp
exposure. Oral surgery may be required to extract teeth, to treat
dental abscesses or to excise oral tumors.
Sedation and general anesthesia for rabbits
Performing dental procedures, such as "teeth
trimming" without anesthesia is often ineffective and can be dangerous
for the rabbit and for the operator. Dr. Kressin discourages this
practice. It is stressful at a minimum and can easily result in injury!
Rabbits can be safely sedated and anesthetized. We prefer not to
withold feed from rabbits in an attempt to avoid bloat. We also do not
withold water to avoid dehydration. It is very important to provide
great care with patient warming during the anesthesia and during the
Balanced anesthesia incorporates analgesia (pain prevention) and
allows minimization of all drugs for smooth anesthesia and
patient recovery. We prefer to premedicate rabbits with ketamine,
buprenorphine and midazalam. Meloxicam, a medication the provides
anti-inflammatory effects and pain relief is also frequently utilized.
Regional anesthesia is also preferred when oral surgery is performed.
Anesthesia induction is by inhalent (Isoflurane or Sevoflurane). We
prefer intubation to protect the airway unless a very short anesthesia
period is anticipated. It is always preferred to minimize the overall
anesthesia time period. For additional information on anesthesia safety
see anesthesia concerns. If you have additional concerns regarding pain management, go to pain related concerns.
Regional anesthesia for rabbits
Regional anesthesia or nerve blocks are
beneficial when performing oral surgery in rabbits. By blocking the
nerve input from the periphery (the teeth and the oral cavity), the
general anesthesia levels can be lowered to increase anesthesia saftey.
Nerve blocks effectively allow early return to eating and reduces bloating problems after anesthesia.
Veterinarians are encouraged to study "regional anesthesia" provided by Dr. Kressin.
Every opportunity to reduce pain in our patients should be implemented when dental or oral surgery is anticipated.
Diagnosis helps determine the prognosis
Radiographs are fundamental and essential to
helping rabbits with dental problems. Non-screened radiographs provide
higher detail and help with the diagnosis of the problem(s). I prefer
non-screened mamography x-rays taken from various positions to evaluate
rabbits. These radiographs are taken with the general anesthesia.
Using radiographs and by performing a detailed intraoral exam, the best
approach to treatment is established. The stage of disease is
determined which offers a long term prognosis.
Grade 1 stage of disease may involve minor malocclusion of incisors.
The ventral border of the mandible is smooth and of normal bone
density. The roots are of optimal length and appear parallel to
adjacent teeth. The occlusal surface of teeth are smooth and linear on
radiographs. The prognosis is good after occlusal adjustments are
made (if needed) and the rabbit is eating an optimal diet.
Grade 2 stage of disease has early radiographic changes. The
ventral border of the mandible is thin. There may be root elongation
and root divergence from parallel orientation of adjacent teeth.
Enlargements of the face or lower jaw may be palpable and there may also
be radiographic evidence of bony growth (enlargement). Occlusal
adjustments may be needed and with the appropriate diet, the prognosis
Grade 3 stage of disease may be significant enough to be resulting
in eating habits and weight loss. These rabbits may have substantial
infectious disease. Radiographs demonstrate further thinning of the
ventral border of the mandible and less overall bone density. Root
elongation may be significant causing pain and discomfort. There is
further deviation from the parrallel arrangement of the teeth. The bony
protrusions (face and mandibles) may be very significant with marked
densities on radiographs. The prognosis is guarded. Bacterial cultures
are indicated in many cases.
Grade 4 is an advanced disease process with obvious clinical signs
of poor health. The ventral mandible has perforation of very thin
bone. There is significant deviation of adjacent cheek teeth from the
normal parallel orientation. The occlusal surfaces appear blurry due to
variable cheek teeth length. Soft tissue abscesses are common.
Surgical intervention along with occlusal adjustments are
indicated. Antibiotic coated beads are chosen based on culture and
sensitivity testing to treat the soft tissue infections. Dental
extraction is often indicated. Rabbits do well with one or two cheek
teeth extraxcted however with multiple extractions, occlusal problems
are common requiring periodic 6-12 week occlusal adjustments. The
prognosis is guarded to poor based on the individual case.
Grade 5 is the most severe stage of dental disease. These animals
have moderate to severe weight loss, excessive salivation, eye and
or nasal discharge with chronic pain. Infection of bone (osteomyelitis)
and soft tissue is present. Radiographic evidence of bone destruction
is severe. The dental arcades align poorly. Fractured and missing
teeth are common. Prognosis is poor to grave.
Radiographs help diagnose jaw (mandibular) and tooth fractures
This patient suffered from a traumatic injury. The mandibular symphysis
was "separated" or "fractured". The left and right mandibles were
mobile and would float independently. The radiograph below demonstrates
the rotated mandible and torn symphyseal tissue.
Paddington was injured and his symphysis was separated.
The symphysis is joint-like and holds the two lower jaws
together. The two lower jaws would move independently.
The symphysis was stabalized and Paddington
was immediately eating.
The radiograph below demonstrates abnormal occlusal alignment.
Occlusal adjustments were indicated and performed. Notice that the
ventral aspect of the mandible (lower) jaw appears smooth and is normal.
Chinchilla dental care