Rodent’s and lagomorph’s dentistry

Rabbits, hares, hamsters,guinea pigs,chinchillas and many other animals belong in the categories of lagomorph and rodents. They have one thing in common that we do not see in dogs and cats: their teeth grow throughout their entire life.Dog, cat and even human teeth grow until they reach their maximum size and then they stop. Rodent teeth can grow up to 2 cm a month – depending on the species and the location of the teeth.

Rodents have evolved to be able to chew a lot of food (typically with low nutritional value). They need to chew all the time. If we tried to do that, we would be left with very damaged teeth soon.

That means that the wear and tear of the teeth must match the growth rate. Otherwise they can have problems like tooth spikes, lacerations from the spikes and overgrown incisors and molars. Also roots can perforate the cortical bone and put pressure on the eyes or tear ducts. Finally abscesses from root deformation and other problems can occur.

While we want to provide our little furry friends with the most paw licking foods, hay should be a big part of their daily nutrition. Overfeeding fruits, veggies and pellets might seem a nice thing to do, but it will make them full and obese. They are also not very keen to chew on the less appetizing hay then. Hay has to be chewed a longer time than any other food. It is done in a circular motion of the lower jaw, what brings ideal trim and wear of the molars. All rodents should be offered unlimited quantities of hay, rabbits and chinchillas are top of the list of animals that need to consume large quantities.

A“perfect rabbit diet” consists of 70% hay, 20% fresh vegetables, 5% pellets and a very small number of treats, like fruits and nuts.  A very good practice is to provide:

  1. Unlimited amount of hay, replacing it once or twice a day,
  2. Fresh veggies and pellets in moderate amounts 2-3 times a day,
  3. The more appetizing food like fresh fruits and nuts in small amounts once or twice a day.

Similar recommendation applies to all rodents, with some differences between hamsters, chinchillas, guinea pigs, etc.

A variety of symptoms can follow abnormal wear of the teeth. The most common are:

  • Reduced food consumption, selective eating or anorexia. This could lead to weight loss.
  • Tooth elongation, usually can be seen on the incisors.
  • Excess salivation and wetness on the chin
  • Nasal or eye discharge
  • Bulging eyes
  • Abscesses in and around the mouth

This is “Jad”, the chinchilla. His owner is doing her best to take care of him. But he was receiving a bigger amount of nuts and treats than he should. This resulted to“Jad”eating less hay and not wearing his teeth enough. That caused two of the molars’ roots to put pressure on the tear duct.

If you notice any of the above, please consult your veterinarian. Incisors are the only teeth that can be seen with direct observation but it is crucial to inspect the molars (cheek teeth). That can be done with a small scope inserted into the mouth for a quick look. Inspecting the entire mouth under sedation is the better way to go if we have any signs of dental disease.  Alternatively, an x-ray of the mouth can be taken.


Lateral x-ray of a rabbit with malocclusion. The incisors and some of the molars had to be removed.

If there are signs of malocclusion like overgrown teeth or spikes on some teeth, it is necessary to correct that. This is usually done by trimming the teeth with a special drill under sedation.If this is something that happens too often, even after correction of the patient’s diet, we would recommend a tooth extraction.


This is how a tooth spice looks like, notice the sharp edges protruding towards the tongue. If this is left unchecked they would traumatize the mouth and the tongue, and possibly stop the rabbit from eating.


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