Teeth are a rabbit’s most famous feature but if something goes wrong it can be disastrous.
The mechanics of rabbit teeth
The layout of rabbit teeth is similar only to other lagomorphs (rabbits, hares and picas). The back teeth, the molars, are used for grinding down hay and other fibrous foods. The upper molars are spaced so they are slightly overlapping the lower molars towards the cheeks.
The combination of incisors and “peg teeth” is only found in lagomorphs. Each of the two upper incisors has a “peg tooth” behind. When the mouth is closed, the lower incisors slot between the upper incisors and the peg teeth. The teeth rub against each other, keeping both upper and lower incisors chisel-sharp.
The incisors are used for snipping off pieces of grass, hay and other plants before passing food backwards to the molars for chewing.
There is a gap between incisors and molars. Rabbits do not have canine teeth.
So that this highly evolved system can work, the teeth need to meet properly. When they don’t, it’s known as malocclusion. Rabbits that have malocclusion will need regular dental treatments throughout their lives. There are no braces for rabbits, so they cannot be brought back into line.
Sometimes rabbits with round faces (lops and dwarf breeds in particular) don’t have enough room for their teeth and they will be crowded and maloccluded. The face shape of wild rabbits is best suited to the number of teeth they have, so if you’re intending to adopt a rabbit, look for one that looks as much as possible like a wild rabbit; it will be less likely to have dental problems.
Long in the tooth
Teeth grow continuously throughout a rabbit’s life. They are worn down at the tops (crowns) by the action of chewing. If the upper and lower teeth don’t meet properly, they won’t wear effectively, and that will cause serious problems. Incisors can grow to astonishing lengths, and molars will develop spurs (sharp points) on the outer edge of top teeth and the inner edge of bottom teeth.
These shards will keep growing, and they’ll dig into the cheeks and tongue every time your rabbit moves his mouth or tries to eat. This will be extremely painful. It’ll restrict your rabbit’s ability to eat, and if you don’t have it treated, the condition will be fatal. There can be problems below the gumline, too, in the bone of the jaws, resulting in root infections which often cause abscesses.
Grass is what your rabbit would eat in the wild more than anything else. And our pet rabbits are only a very short step away from their wild cousins, so their diet should match. It’s difficult to provide enough grass all year round, and hay is an excellent substitute, so for simplicity, we’ll talk about hay here when we also mean grass.
Hay contains a special sort of fibre that’s called ‘long fibre’. It’s tremendously important for the gut to work properly, but also for your rabbit’s teeth because it needs to be chewed side-to-side, and that is what wears those molars down. No other food does this. It contains silicas too, and those also help with the wearing down of molars. Other foods aren’t chewed with the same side-to-side action and so don’t have the same teeth-wearing effect.
If your rabbit isn’t eating properly then there is a good chance that teeth may be the problem. Even rabbits with properly aligned teeth and a great diet can still get the odd spur, so if there is a loss of appetite, ask your vet to take a look at all the teeth.
Regularly feel your rabbit’s jawline. If it’s bumpy, you should ask your vet to examine his teeth. Bumpy jaws often mean overgrown roots and possible infection.
If your rabbit starts to have runny eyes, again, suspect a problem with his teeth. If upper roots overgrow, or if there is infection in the tooth roots, his tear ducts can become blocked and tears will run down his face rather than draining into the tear ducts and down his nose. If eyes are runny, ask your vet to have a look at the teeth.
Sometimes a tooth will be lost. This is more common in older rabbits, and especially if they have had dental problems during their lives. The tooth that grows under (or above) the missing one won’t have anything to rub against and so it won’t wear down and will grow excessively. It will need to be burred regularly (see Treating Dental Problems below).
Don’t leave any suspected dental problems to sort themselves out…they won’t! Your rabbit will be in great discomfort, and things will only get worse. The sooner treatment is given the better, and more serious problems can often be prevented by keeping on top of the less serious ones.
The Vet will probably use an Otoscope (pictured right) to get a good look at the back teeth and to see whether there are any abrasions inside your rabbit’s mouth. Most rabbits aren’t too keen on Otoscopes but it’s a necessary evil; rabbits go downhill very fast when dental problems start to make it difficult to eat.
If a dental is needed, the vet will anaesthetise your rabbit and put a gag into his mouth to keep his jaws open so she can get a good look inside the mouth.
Teeth should NEVER be clipped. It can cause splitting, and that can let infection into the root of the tooth. Instead they should be trimmed using an electric burr tool, under anaesthetic, where there is much less danger of your rabbit moving his head and getting cut on the soft tissue inside his mouth.
Other impacts of dental trouble
There is a network of cavities within a rabbit’s head and infections are easily spread between them. This means that dental problems can have knock-on effects.
Infections in tooth roots are often linked to other serious problems including ear infections, respiratory infections, retrobulbar (behind the eye) abscesses and even middle and inner-ear infections leading to head-tilt.