Rabbits are estimated to have been around for 40 million years, which is astonishing if you consider that modern humans, anatomically similar to our current species, are thought to have existed for only 300,000 years.
When we consider the anatomy of a rabbit, in particular its teeth and how they function to process its food, we need to understand that functionally, a rabbit’s anatomy has been largely the same for 40 million years. Both wild and domestic rabbits have continuously growing teeth and have done since the species evolved. But this means we need to work within those limits!
So have there been any changes in domestic rabbit’s dentition?
Functionally no, however breeding of domestic rabbits for certain characteristics has led to variations in skull size and the development of some brachycephalic breeds, such as Lionheads. These rabbits have smaller heads and shortened, wider, skulls, but the same number of teeth. This can lead to issues such as misaligned teeth and subsequent overgrowth of teeth, as they are unable to wear as they normally would.
It is important to note however that all breeds of rabbits can have misaligned teeth, and not all brachycephalic rabbits will have dental issues, in fact recent research has found that brachycephalic breeds are not anymore likely to have dental issues than longer-faced rabbits. The key point here is that the misalignment of teeth can cause an issue for rabbits.
Why are misaligned teeth an issue?
Rabbits have teeth that continuously grow, unlike dogs and cats who have teeth that they are born with and if they get damaged or wear away there is no reserve. This is good as it allows rabbits to eat and chew more abrasive materials such as hay and long fibre grass and roughage without the risk of their teeth wearing away, and this is exactly why they have these teeth, to ensure they can eat the foodstuffs they need and access the nutrients necessary for their health.
However, if these teeth are not in alignment then the abrasive surface needed to wear down the foodstuff to make it edible, which is created by the upper and lower tooth grinding the foodstuff, does not exist.
This results in the rabbit being unable to eat the foodstuffs it needs for a healthy diet, and also means that there is no wear to the continuously growing teeth it has in its mouth.
Without wear to these teeth, they continue to grow and when they run out of space in the mouth begin to damage other structures as the roots erupt into the soft tissue structures in the face, which can include the sinuses, eye sockets and tear (nasolacrimal) ducts.
The result of this overgrowth and damage to structures can often be infections and abscess formation. Unlike dogs and cats, rabbits have very hard pus, so the abscesses often form solid masses or lumps that need surgical removal, as they can’t be drained and flushed in the same way they can in other animals.
Is it just misalignment of teeth that causes rabbits teeth to overgrow, or can other things cause this too?
No, misalignment of teeth is one possible cause of overgrown teeth and subsequent damage and abscesses, but there are other more common factors that lead to this occurring in rabbits. These include:
Diet
A rabbit’s diet is critical to its health, and especially to its dental health. As discussed above, rabbits have developed over millions of years to have teeth that can cope with abrasive materials and will continue to grow to prevent them running out of tools to breakdown their foodstuffs.
These teeth have been developed with the intention that the rabbit will eat fibrous foodstuffs such as hay, grass and leafy greens. All of these contain cellulose and indigestible fibres which require grinding and breaking down by the teeth to access the nutrients.
If a rabbit is not fed these high fibre materials and instead eats easily digested foodstuffs such as grains, cereals, and muesli mix, then their teeth do not need to do much work to break down the foodstuffs so they get a lot less wear.
Even though the rabbit’s teeth are not being worn down as much as they should be by the food, they continue to grow as that is what they are naturally programmed to do. This then results in the same issues of overgrown crowns and roots and damage to surrounding structures in the head.
Pain
If the rabbit as oral, facial or dental pain they may be more reluctant to chew with their teeth and may favour areas of the mouth that are less painful, resulting in uneven wear across the teeth. If the rabbit uses their teeth in this way then the teeth which are not used as much are likely to overgrow and cause issues.
Causes of pain can vary, but can include dental abscesses, dental infections, temporomandibular joint pain or damage, and skull trauma.
Missing teeth
Rabbits’ teeth work in pairs to grind down food as we have discussed. If one tooth in that pair is missing, for example the molar on the mandible is present but the corresponding tooth in the maxilla is not, then the molar on the mandible is likely to overgrow. This is because the tooth that would normally be above it, working with it to grind down food, is not present. As a result, the remaining tooth in that pair is not worn down and will overgrow.
What are dental spurs in rabbits, what causes them, and why are they an issue?
Dental spurs are additional pieces of tooth that grow when the molar teeth wear unevenly. This can occur for many of the reasons discussed already, inadequate diet, malocclusion of teeth, missing teeth and pain. As the molars only partially wear areas of the tooth crown overgrow resulting in a phenomenon called dental spurs.
These spurs can cause damage to the soft tissue structures in the rabbit’s mouth including the teeth and cheeks, and cause pain and infection. The continuous uneven wearing of the teeth and pain from spurs can further enhance dental disease in rabbits, and result in more tooth overgrowth.
In severe cases of dental disease due to spurs, overgrowth of crowns and/or roots or a combination of factors, rabbits can stop eating which will often result in the gastrointestinal tract of the rabbit slowing down or stopping, known as gastrointestinal stasis. This is a life-threatening syndrome and needs to be addressed immediately.
How are dental issues treated in rabbits?
Full dental examination in rabbits often requires a general anaesthetic or sedation to enable the veterinarian to look inside the rabbit’s mouth and assess the condition of their teeth.
Treatment of dental disease often involves surgical intervention using a high-speed dental bur to remove dental spurs and reduce the height of overgrown teeth. In certain situations, teeth may need to be removed if the roots of the teeth have become infected or are causing damage to surrounding structures. The veterinarian will assess this by performing dental x-rays of your rabbit’s mouth.
Your rabbit will need pain relief and, if there is evidence of infection, may require antibiotic treatment as well. If abscesses are present, surgery is often required to remove the infected tissue.
How can you prevent dental issues in rabbits?
Prevention is always better than cure. The best way to prevent dental issues in rabbits is to ensure you are feeding them the correct diet. As a rough guide, every day rabbits should have access to unlimited hay and grass, approximately a handful of leafy greens and one tablespoon of complete rabbit nuggets as well as unlimited access to clean fresh drinking water.
You can read more about the appropriate diet to feed a rabbit here.
Getting your rabbit regularly health checked by your veterinarian is also important to spot any issues early. This is especially important if your rabbit has had previous dental issues or tooth removals, as they will be at higher risk of having further dental issues in the future.
If you notice your rabbit eating less, chewing on one side of the mouth, dropping food, or drooling from the mouth these can all be signs of dental issues. It is important if you notice any of these signs that you get your rabbit checked by your veterinary surgeon as soon as possible so any issues can be addressed.
Summary:
- Rabbits teeth continually grow
- Dental disease is common in pet rabbits
- There are a number of factors that can lead to dental disease in rabbits
- If your rabbit has dental disease it is important they are treated by a veterinary surgeon as soon as possible
- Ensuring your pet rabbit is fed the appropriate diet is one of the most important factors in preventing dental disease
Further reading
Rabbit dentals: More than just a “tooth clip”
Pet Health library: Rabbit Dental Disease
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