Pet mouse teeth can be downright problematic. Not all exotic pets have problems with their teeth but sometimes pet mice do. Mice have some teeth that grow continuously throughout their lives and these teeth may periodically require tooth trims if they are not naturally worn down, are damaged, or if your mouse has a tooth alignment issue (malocclusion).
Dogs and cats are born with no teeth, develop deciduous teeth, and then lose those baby teeth so that their adult teeth can take their places.
Mice, on the other hand, only have one set of teeth their entire lives. Their monophyodontal mouths start showing teeth at as young as ten days of age. These teeth, twelve molars and four incisors, remain in your pet mouse's mouth for the rest of its life. The molars never grow but the incisors continuously grow, sometimes causing problems for your mouse.
The incisors of a mouse are naturally colored yellow and are harder than a human's teeth. Their bottom incisors are almost twice as long as their upper incisors and much of the incisors are hidden underneath your mouse's lips. In order to get a good look at their teeth, you'll need to gently pull back their cheeks and lips to make sure the teeth aren't curling up and back into your mouse's mouth or into the side of their cheeks. Teeth will grow very quickly with an entire tooth turnover rate of 35-45 days.
The incisors, or front teeth, are usually easy to identify when they become grossly overgrown.
They will usually grow so long that they begin to curve and stick out between the lips where they can become stuck on things, or worse yet, grow into the gums or roof of your mouse's mouth. The molars, or teeth in the back of the mouth, do not grow so therefore they are not a problem like they can be in guinea pigs and rabbits.
Most mice will wear their incisors down appropriately when they gnaw on their food but some mice are born with misaligned teeth, jaws, or suffer trauma at some point in their lives which inhibits normal gnawing action. Some people will elect euthanasia if their mouse is diagnosed with malocclusion due to the regular tooth trims they will have to endure throughout their short lives but the teeth can be managed with the help of a veterinary professional.
Incisor Tooth Trims
If done correctly, tooth trims are not painful. There are two common methods used to trim incisors. The first is by using regular nail clippers or blunt scissors to cut the teeth like you would a toenail. These methods are not the preferred ways to trim teeth. There is a high risk of cracking or splitting a tooth because of the force needed to use the clippers or scissors and can cause pain if the tooth is split up to the nerve or is trimmed too short. The second method is by using a handheld rotary tool, like the Dremel, with a cut-off wheel to slice the excess tooth off. This method does require a bit more skill and anesthesia or sedation for mice since their mouths are so small but can be easily performed by a trained exotics veterinarian (find one near you) or veterinary technician.
By using a rotary tool no trauma will occur to the tooth or nerve when cut. The only concerns are for trauma to the gums or lips if the wheel accidentally grazes them, or if the tooth is trimmed too short. This is why it is necessary to anesthetize mice prior to tooth trimmings and to carefully trim their teeth.
Owners of mice and other exotic pets with teeth that continuously grow must be aware of the possible complications regarding their pet's teeth. Without the proper attention, overgrown teeth can cause serious trauma, anorexia, infection, pain, and even death from the inability to chew and swallow. Thankfully the problem of overgrown teeth is easily controlled with regular tooth trims and monitoring of tooth length.