dental disease in bunnies

Rabbits are herbivores. They are designed to spend 8 or 10 hours a day grazing. Their teeth grow throughout their life – and are worn down by the constant abrasive effects of grass (silicates in the grass blades do the job)

The incisor teeth at the front of the mouth are every dependant of each other to keep a sharp set of blades present for cutting grass (for chewing by the molar teeth)

As a prey species, a rabbit in the field grazing is always in danger – they therefore eat as much as possible in as little time as possible – then disappear down their burrow to digest their food – and do whatever else comes naturally to bunnies when they  are not under threat.

Whilst ruminants such as cows regurgitate food matter, allowing them to chew it again, the rabbit adopts a different technique – they pass food matter out of the body at night as soft pasty balls called caecotropes, which they eat, so that the food is sent through the guts a second time

If we feed bunnies a diet that is short of fibre (e.g. muesli-mix bunny foods ) then instead of the teeth wearing against each other for 10 hours a day, the bunny scoffs his food in 10 minutes. As a result, the molar teeth are not worn down. If this happens, the jaw cannot close properly, so the incisor teeth no longer meet. If they don't meet, they don’t keep each other in check, and they grow and grow until they curl either into open space, or into the opposite jaw.
These teeth may then either head for the heavens, or curl around into the opposing jaw, causing terrible eating problems. A bunny with such teeth cannot groom (its coat becomes matted) nor can it consume its caecotropes. These then get splodged around the bunny’s back end, getting smelly and attracting flies. The next step is flies laying their eggs in the soggy mess, with maggots (and usually death of the bunny) following.

wild rabbit lower jaw

pet rabbit lower jaw

wild rabbit

lower incisors meet inside of upper incisors - peg teeth stop them going into roof of mouth

 

pet rabbit

lower incisors are outside upper incisors, so they no longer wear against each other

 

The molar teeth that grow too long get pushed against the opposing teeth, pushing each other out of line. Not only does this lead to the teeth getting pushed out of the bottom of the jaw, but they also lose their perfect alignment along the jaw. Instead of the cheek teeth creating a perfectly aligned ribbed cutting surface, they can grow inwards or outwards, creating sharp spurs that stab into the tongue or the cheeks. This is very painful – the rabbit loses weight, stops eating, and often ‘slobbers’ 

 

dental spur going into cheek dental spur cutting into tongue

Sometimes the first sign of dental disease is wet front paws, from where the bunny rests his chin. If you find this on your bunny, take him straight to the vet!

Once a tooth has grown sideways, it will never return to its normal position. However, removing the tooth is not a solution, as the opposing tooth then gets nothing to wear against and it gets too long.

The tooth roots that pierce the jaw often end up developing abscesses, which can in turn lead to infection of the surrounding bone (oesteomyelitis). This situation is frequently impossible to resolve properly, and the end result is usually a dead bunny!

Look how thickened the jaw bone is (-yellow arrows) compared with the wild bunny  (left of picture)

If the upper incisor teeth move in the jaw, they can block the tear duct, leading to poor drainage of the tears, and eye infections.

A rabbits gut is designed to digest fibre – this is broken down naturally by bugs in the rabbits gut. If there is not enough fibre in the diet, the balance of these bugs can be lost, causing tummy upsets – which can be life-threatening.

The moral : rabbits eat grass – get the diet, and all these problems will be avoided.

To summarise all these problems

  • Tooth spurs cutting into the tongue/cheeks
  • Incisor teeth growing round into the jaw
  • Inability to groom
  • Inability to eat caecotropes – weight loss from loss of nutrients
  • Pasting of caecotropes around rear end,  fly strike, maggots
  • Abscess from tooth roots
  • Eye infections
  • Tummy upsets

 

So how should I feed my bunny?
Bunnies should  have access to grass, or high quality hay, at all times. You can feed vegetables and herbs such as dandelions, but fruit is not advised (nor yoghurt drops or chocolate!).

Pelleted feed is not really needed, even for young growing bunnies. If you do want to feed pellets, how do you choose? Take a look at the chart below.

At the bottom you will see two top quality hay analyses. Bunnies are selective when eating, so they may pick some of the younger grass, which will have a higher protein level and lower fibre levels, so let's say 28% fibre, 12% protein. Remember, bunnies are not grain eaters. 

Let's see how the popular rabbit foods fare!!
food main ingredient protein fibre
Pets at Home premium rabbit meusli Oatfeed , Wheatfeed 13.5 9.5
Burgess light nugget Cereal Grains , Dried Forages 12 18
Chudleys rabbit royale Grass, Wheat, 12 6
Russell Rabbit  Alfalfa , Wheat 14 14
Wagg optimum premium  Wheatfeed , Oatfeed 13 17
Pascoes bunny balance dried forages , cereals 12 15
Oxbow Bunny Basics t Timothy Grass Meal , Soybean Hulls 14 25
Mid bloom 'smooth-brome' hay grass 12 32
Mid bloom 'timothy' hay grass 8.6 32

You will see that the only food that comes anywhere near to the fibre content of hay is Oxbow Bunny Basics, and this is the only brand of pelleted food that we sell (it also does not contain cereals).

There are 2 versions - Bunny Basic 15/25, for young rabbits, and Bunny Basics T for adults.

The best and most consistent hay we have found is also from Oxbow - always green, sweet smelling, and bunnies love it. Not cheap, but they eat it all. We suggest using a cheap hay for bedding and extra nibbling, with Oxbow hay in a rack off the floor.

It is also important that your bunny gets out in the daylight, letting it produce its own vitamin D, ensuring it can absorb the Calcium it needs.