Pet rat teeth can be problematic. Not all exotic pets have problems with their teeth, but since rats have some teeth that grow continuously throughout their lives, these teeth may periodically require care. Knowing what to watch for in your pet rat's mouth can help avoid serious trauma to its mouth.
What Kind of Teeth Do Rats Have?
Dogs and cats are born with no teeth, develop deciduous or baby teeth, and then lose those teeth so that their adult teeth can take their place. Rats, on the other hand, only have one set of teeth their entire lives and these teeth appear in their mouths as young as eight to ten days of age. These teeth consist of twelve molars and four incisors and they remain in a pet rat's mouth for the rest of its life. The incisors continuously grow while the molars do not, but this continuous growth of the front teeth can cause problems for your rat.
Examining Your Rat's Teeth
The incisors of a rat are naturally colored yellow and are harder than a human's teeth. Their upper incisors should be about four millimeters long and their bottom incisors almost twice that length at seven millimeters long past the gumline. Much of the incisors are hidden underneath your rat's lips, therefore 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 rat's mouth or into the side of their cheek.
Overgrown Rat Teeth
The incisors, or front teeth, are easy to identify when they become 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 rat's mouth. The molars, or teeth in the back of the mouth, do not grow, so they are not a problem for rats like they can be in guinea pigs and rabbits.
Most rats will wear their incisors down appropriately when they gnaw on their food, but some rats are born with misaligned teeth, jaws, or suffer trauma at some point in their lives which inhibits normal gnawing action.
Rat 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 dog nail clippers to cut the tooth like you would a toenail. This method is not the preferred way to trim teeth though and an exotic animal veterinarian will highly recommend against this! There is a high risk of cracking or splitting the tooth, because of the force needed to use the clippers. This method can cause pain if the tooth is split up to the nerve or trimmed too short. It can also break the joint between the jaw bones and result in abnormal growth permanently.
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 rats since their mouths are so small but can be easily performed by a trained veterinary professional. By using a rotary tool, no trauma will occur to the tooth or nerve when cut, assuming it is done correctly. 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 or sedate rats in order to properly and safely trim their teeth.
Owners of rats 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, infections, 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.
Preventing Overgrown Teeth in Rats
The best way to keep your rat's teeth at a normal length is to provide them with something to chew on. Safe wood, rat pellets, and toys that allow a rat to gnaw will naturally wear these teeth down to a safe length. Sometimes rats are simply born with malformed teeth due to inbreeding though, and it may be difficult for them to properly chew and wear their teeth down.
Mancinelli, Elisabetta, and Vittorio Capello. Anatomy And Disorders Of The Oral Cavity Of Rat-Like And Squirrel-Like Rodents. Veterinary Clinics Of North America: Exotic Animal Practice, vol 19, no. 3, 2016, pp. 871-900. Elsevier BV, doi:10.1016/j.cvex.2016.04.008
Routine Health Care of Rats. Merck Veterinary Manual.
Routine Health Care Of Rats. Veterinary Manual, 2020