Guinea Pig Oral and Dental Health Care
Guinea Pigs have continually growing and erupting teeth. They have an elodont dentition which consists of aradicular hypsodont incisors and cheek teeth. This dynamic (changing) relationship between the upper and lower teeth can result in malocclusion development. In the guinea pig, the growth rate of these aradicular hypsodont teeth may not be equal with the eruption rate. This results in greater curvature of the cheek teeth. The severity of malocclusion of the cheek teeth may not be as easily identified as in the chinchilla or the rabbit. The guinea pig may not have palpable protrusions at the ventral aspect of the mandible, or at the lateral aspect of the maxilla as in the chinchilla or the rabbit. The inability to diagnose these malocclusions early can dramatically reduce the effectiveness of treatment.
Feeding long stem hay and fresh vegetables helps with normal occlusal wear and in maintaining normal occlusion.
Guinea pig oral exam
The extraoral (outside the mouth) exam provides some indication of problems that may be found on the oral exam. We observe for facial symmetry and discharges from the face or chin. We look for sores in the mouth and the general shape of the cheek teeth. Anesthesia will be required for a full oral exam.
According to Margherita Gracis DAVDC, "published data show that only 30% of oral mucosal lesions are detected during the initial (non-sedated patient) exam, and 50% in anesthetized patients." It is suspected that these problems exist in chinchillas and rabbits as well.
Dental formula for guinea pigs and chinchillas; 2(I1/1 C0/0 PM1/1 M3/3) = 20
I stands for incisor teeth.
C stands for canine teeth.
PM stands for premolar cheek teeth.
M stands for molar cheek teeth.
The formula is designated as fractions to indicate the upper and lower dental arcades.
The 2 in front of the formula is for the left and right upper and lower dental arcades.
Survey skull radiography is the basic diagnostic tool used to complement the oral exam. Radiography helps us understand the prognosis, determine the level of dental care needed, and whether treatment is logical or feasible. Early diagnosis and treatment can also improve the long term prognosis.
Computed tomography (CT scans) has been shown to be useful in rabbits and chinchillas, and would be beneficial for guinea pigs as well. Magnetic resonance imaging and ultrasonography may help with the evaluation of soft tissue structures of the head. These imaging modalities are all available to us in Milwaukee.
Initial extraoral evaluation.
An otic or vaginal speculum helps view cheek teeth.
Anesthesia in Guinea Pigs
Bloat is a serious problem in guinea pigs. We attempt to avoid feed witholding to minimize the possibility of bloat. Since guinea pigs do not vomit, feed witholding can be minimized or avoided. We also do not restrict water to avoid dehydration.
I prefer to use balanced anesthesia with analgesia (pain relief). We like to use a premedication combination of buprenorphine with midazalam and ketamine. This combination provides sedation and analgesia. Local or regional anesthesia is also routinely employed when oral surgery is required. The premedication also allows for IV catheterization. Fluids are administered via a Heska fluid pump, and the rate is based on pre-operative blood evaluations. Anesthesia induction is by mask inhalent (sevoflurane or isoflurane). We monitor the patient using a Cardel 9405. This provides pulse oximetry, blood pressure, temperature, respiratory rate, heart rate, electrocardiogram (ECG) and capnography, however, capnography is inconsistent. A straight 2mm endotracheal tube may be passed (blindly).
Cardel 9405 veterinary patient monitor
Heska IV fluid pump allows precise fluid delivery for patient safety.
For additional information about anesthesia safety; go to anesthesia concerns and if you are worried about pain,
go to pain related concerns.
Specialized equipment for visualization of the cheek teeth
Since the four incisor teeth are the only teeth easily viewable, specialized equipment is essential in providing oral care for guinea pigs.
Mini is in position for an occlusal evaluation. Note the inability to view cheek teeth. Guinea pigs hold feed
in the cheek pouches. This material must be removed to see the cheek teeth clearly.
This view demonstrates improved visualization of the cheek teeth. Note the left upper cheek teeth are not in straight alignment. The projections seen on the left upper dental arcade (left side) are abnormal "spurs" or "points" that require occlusal adjustment. Great care is taken to avoid injuring the tongue or soft tissues. A cotton tip applicator is holding the tongue away from the working area.
This view demonstrates the relationship of the right upper dental arcade (left side of photo)
to the right lower dental arcade (right side of photo)
An example from another case. Notice that the tongue has been trapped due to bridging created from the cheek teeth
This photograph demonstrates the one type of crosscut fissure bur we use to adjust
the cheek teeth occlusion. Try to appreciate the limited working space available
in the guinea pigs mouth, and the limits of visualization in the working area.
For additional information; go to equipment improves oral exam
Rabbit & Rodent Dental Care