Dental disease in rabbits
What is so special about rabbit teeth?
Healthy teeth are essential for a healthy rabbit. Thankfully there is now greater knowledge about the mechanics of rabbit’s teeth and the nutritional requirements of rabbits. This means that we are seeing fewer dental problems than in the recent past and our pet rabbits tend to be living longer as a result.
Rabbits have deciduous teeth (‘milk teeth’) but these will never be seen by an owner as they are lost at or around birth. During the first few weeks of life the adult or permanent teeth start to erupt. These teeth differ from human teeth in that they erupt or grow continuously throughout the life of the rabbit.
The teeth that can be seen by owners (if their rabbit will allow!) are the incisors. There are two top and two bottom incisors on each side of the mid-line. These are closely followed by the peg teeth at the top only, one on each side. There is then a gap called the diastema, which is really useful for giving medications or syringe feeding! Behind this at the top there are three pre-molars and three molars whilst at the bottom there are two premolars and three molars. The molars and pre-molars together are called the 'cheek teeth'.
Each tooth is constantly growing. The usual rate is about 2mm per week but this can be increased when there is dental disease present. To prevent overgrowth there must be a constant wearing down of the teeth. The incisors wear against each other and the food which they shear. The cheek teeth are worn by the grinding effect of the teeth against each other and the fibrous and gritty content of their diet. For the wear to be even and prevent sharp spikes and spurs developing on the teeth it is important that the teeth are perfectly aligned. In the wild, if teeth are not perfect then the rabbit will not survive long enough to pass on its genes for bad teeth to future generations. However, domestication has led to breeding of rabbits against this natural selection, so certain breeds are more predisposed to dental disease, especially the miniature breeds and the lion-heads. In addition, rabbits have a very complicated calcium metabolism. If a rabbit has a diet deficient in calcium then its bones become soft and the teeth can move slightly out of position. This means that the wear becomes uneven and spurs appear.
There are three different appearances of dental disease which may be seen
individually or in combination.
- Overgrown and misshapen incisors. If your rabbit allows handling you will be able to see its front teeth. If these are misaligned they will soon over grow into 'tusks'. These teeth can prevent the rabbit from picking up food, drinking and grooming properly. They may grow into the nearby soft tissues causing infections. They are also prone to getting caught and broken causing painful damage. Affected teeth may also be discoloured and ridged.
- A mismatch in the constant wear on the cheek teeth can cause sharp spurs and spikes to occur in the crowns. On the lower teeth these can cause ulceration on the tongue and from the upper teeth they can cause ulceration in the cheeks. This makes it extremely painful for the rabbit to eat.
- When the bone becomes soft the roots of the teeth can also move. This can lead to painful abscess formation and in some cases to blockage of the tear ducts which in turn can lead to sticky eyes.
How do I know if my rabbit has dental disease?
We strongly recommend regular examinations with a veterinary surgeon in order to prevent dental disease and for early detection should it occur. Remember rabbits are 'prey animals' which means they are very good at hiding illness from potential predators (and their owners!). Signs to look out for are weight loss, salivation (drooling), eating less or a change in diet preferences, sticky eyes, reduced grooming (often noted as mite infestations and scurf) and having a dirty bottom (possibly causing fly-strike).
How is dental disease investigated and treated?
There is a limit to what can be seen in the conscious rabbit. An anaesthetic is often required to allow full inspection of the cheek teeth. Dental radiographs (X-rays) allow visualisation of whole teeth, including the roots.
Incisors can be trimmed back to an appropriate length by using a burr on a dental drill, a procedure which can often be performed in a conscious rabbit. Never be tempted to clip teeth yourself as this can cause painful damage to the tooth. As the teeth continue to grow this treatment tends to be needed on a regular basis. The alternative to regular burring is removal of the incisor teeth. This procedure requires a general anaesthetic. The teeth are gently removed and then the germinal roots are destroyed to prevent regrowth. After this procedure the rabbit learns to pick up its food with its lips rather than its teeth.
Treatment for the cheek teeth involves rasping and burring affected teeth to appropriate shapes and lengths. Tooth removal in this case is problematic although occasionally necessary. Abscesses also require treatment. All treatment for molar and premolar teeth requires a general anaesthetic. Again, due to continued growth of the teeth, further treatment is usually required. Care must also be taken to ensure that the rabbit is not in chronic (long term) pain, and it can be very difficult to interpret this in rabbits.
How can I stop my rabbit getting dental disease?
Feeding your rabbit appropriately is the most important thing you can do to prevent dental disease developing.
Firstly, feeding plenty of good quality grass and hay will provide plenty of fibre and mineral particles to actively wear the cheek teeth down. This should be the main component of your rabbit's diet.
Most rabbits also require a small quantity of dry food. Unfortunately, the muesli type diets look attractive but the majority of rabbits fed this diet are left severely low in calcium due to selective feeding - invariably they will pick out the tasty colourful bits and leave the boring brown bits which have the additional calcium! We recommend feeding a completely pelleted diet in addition to grass and hay, so that you know your rabbit is getting a balanced diet.
Please use your regular visits to the vets to discuss your rabbit's diet and dental health.
If you have any concerns about your rabbit's oral health, please do not hesitate to contact us.
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