Rats are members of the rodent family and all of the species within it, from the tiniest one ounce mouse to the giant five stone capybara need to gnaw or chew to keep their teeth in good order. They only have one set of teeth in their lives which keep growing and each tooth has to meet the one in the opposite jaw to keep them ground down and cutting and gnawing properly. If one is broken or slightly misaligned, the other will keep growing and eventually the rat will be unable to eat properly.
What to watch out for
If a rat is suffering from a malocclusion it will feel very uncomfortable around the mouth and may paw at the area repeatedly. If a tooth has overgrown it may be causing sores in the mouth and these will be very painful. Not only that but the rat will be off its food and may exhibit behavioural changes linked with stress and pain. A rat’s teeth grow 4-5 inches a year, which is about one tenth of an inch a week, so overgrown teeth will show a reasonable length of time since the problem began if they have started giving trouble with sores in the mouth. A vigilant owner will hopefully spot the problem earlier than this. A proper check of the teeth at least once a fortnight will prevent any tooth problems becoming difficult to treat.
Dealing with overgrown teeth at home
If a rat is troubled with overgrown teeth and the malocclusion is caused by a misaligned tooth rather than a temporarily missing one following an accidental break, the teeth will need to be regularly trimmed. This can be done at home but only if the owner feels one hundred percent confident that they can do it. This is not something for the squeamish and it is certainly no good to half do it and chicken out. The trim must be quickly and cleanly done with no twisting of the tooth; twisting will only make matters worse as the malocclusion will be made more severe. A rat has no nerves in its teeth so it will feel no pain, but obviously having to be held firmly, possibly wrapped tightly to stop it wriggling, will be stressful for it so it is essential to be as quick as possible. It is best if the vet does it the first time and trains the owner to do it in the future.
The best things to use for trimming teeth are dog toenail or ordinary fingernail clippers. A dental burr can be used as well. If two teeth top or bottom need trimming, a pair of guillotine style dog nail clippers will do a very good job and it will mean that the pair are even because you will only need to make one cut. Rat teeth are too hard to cut; what the clippers do is break it off at the correct point. It is important to try and maintain the original bevel on the tooth. This gives it the best chance of grinding normally later on. It is obviously very important to make sure that the lips and tongue are kept out of the way when clipping or a sore mouth will be made much much worse. This is really always a job for two people.
If the mouth was sore before the condition was found and corrected, the rat will need help with pain until healing takes place. This can be obtained as a prescription from the vet but some people find any infant pain reliever will have a very good effect. The rat needs to be given softer food until the teeth are level again and the checking of the mouth should be more frequent until the teeth are grinding again and meeting level. If the malocclusion is not a result of accident the teeth may never realign and in this instance the trimming will have to be done very regularly; this could be every two months, if you are lucky, perhaps every two months will be enough. After the trimming, the tooth edge will be jagged. If the rat is still feeling cooperative after the trim, it may be possible to file them smooth. If not, then giving clean bones for the rat to chew will quickly smooth them off. If the mouth is very sore the gums bleed slightly – as sometimes happens – then the rat will probably benefit from having its mouth rinsed out with saline.
Prevention of dental problems
This is much more easily said than done. Some rats have a genetic predisposition to malocclusion and if this is the case the owner should take steps to make sure that that particular line is not bred from. Accidents happen and if a rat breaks a tooth then it is just one of those things; if it keeps happening it would be a good idea to examine the habitat to see if there is one particular section that is unsafe. If the rat is not eating properly because of sores in the mouth, the teeth may overgrow because the food is not sufficient to wear them down. This will become a vicious circle, because the teeth may grow into the mouth and it will become even more sore. If the rat is suffering from mouth sores a lot it is probably time to examine its diet and make sure that it is not suffering from a vitamin deficiency. Finally, it sometimes happens that a rat has a malignancy of the jaw. Surgery is not really practicable in these cases and the kindest thing to do will be to euthanize the animal, as it will be unable to eat properly and will become weaker and weaker very quickly.