Rabbit Health Section – Feeding Rabbits

RABBITS EAT GRASS
“Rabbits eat grass.” This simple statement sums up all that you need to know about the correct nutrition of pet rabbits. A full explanation of this statement follows, but basically that is it. Rabbits eat grass, and grass is what rabbits eat!

The pet rabbit is descended from the wild rabbit, and is thought to have evolved on the Iberian peninsula, (Spain and Portugal). After the end of the last ice age, it migrated to the rest of Europe, and was introduced to other continents either deliberately or accidentally. While evolving on the Iberian peninsula, the rabbit became very well adapted to living on poor quality grasses, high in fibre and low in nutrients. Since their migration throughout the world, the rabbit’s basic internal workings have not changed substantially, and wild rabbits spend a very considerable part of their time eating and looking for food.

Consequently, the pet rabbit, like its wild cousin, is well adapted to make the most of what vegetation is available. Rabbits have two main adaptations for this way of life:

1. All the teeth, front and back grow constantly. This allows the rabbit to grind coarse vegetation into very small pieces for efficient digestion, without wearing away its teeth.

2. The coarse fibrous material is propelled very rapidly through the rabbit’s intestines, and is expelled as the typical hard, dry, dark coloured droppings. The lighter, more easily digestible fibre is passed into a very large caecum, which is a blind-ending chamber within the intestines. Here, it is fermented by bacterial action and turned into materials that can be absorbed and used by the rabbit. However, the caecum is positioned after the part of the intestines that absorbs nutrients, so the caecal products (called caecotrophes), are passed through the anus separately from the droppings, (usually at night), and eaten. Caecotrophes are soft, light brown in colour, and covered with mucus. They are a very important part of a rabbit’s diet.

So, you can see how the rabbit manages to subsist on food materials that other species cannot. Few other species have all their teeth growing constantly, and caecotrophy is unique to the rabbit.

What About Rabbit Food?
We have been conditioned by many different pet food manufacturers to expect to feed our pets out of a tin, or a bag. For dogs and cats, this is no bad thing, and great improvements in the nutrition of these species have been made by pet food companies. Rabbits are not like dogs or cats, and in our view, it is not possible to formulate a complete all-in-one diet for rabbits, except for grass.

There are two main types of rabbit food: those that resemble muesli in appearance, being a mixture of grains, pulses, pellets and biscuits; and homogenous pellets, that all look the same, and resemble many of the complete dry dog and cat foods. Looking at each of these in turn, they both have problems.

Muesli Type: Rabbits are selective eaters. Just like most other species, (and especially human infants), they will eat the bits that they like, and leave the bits that they don’t like. When the food was formulated it was made so that the whole diet was balanced. When the rabbit starts leaving bits, it unbalances the diet, and this can have disastrous consequences. In particular, rabbits appear to leave the pellet portion, and it is often this that has added vitamins and minerals. Calcium deficiency is extremely common in the UK pet rabbit population because of this. Another problem with this type of food is the lack fibre. The manufacturer wants to market these foods as complete, so they have to add fibre. This is added as small pieces of hay, typically alfalfa hay, that is high in protein, and calcium. However, the hay is less palatable than the grains, often gets left, and the rabbit’s diet lacks the necessary fibre that is so important to stimulate normal intestinal movements. Remember, it is fibre that is propelled rapidly through the intestines. Without the fibre, the intestinal health is severely adversely affected.

Pellets: With these, the manufacturers have two choices. They can include large quantities of fibre, at high cost, and at the expense of palatability (which means they would be producing an expensive food that rabbits don’t like), or they can produce a concentrated, low fibre ration that is to be fed along with a fibre source such as grass or hay. This is fine in principle, but in practice, people give far too much of the pellets because the rabbit likes them, (and we all want to see our pet enjoying its food), with the result that the rabbit fails to eat sufficient fibre.

Both Types: Now we come to the crux of the matter, and the reason why it is not possible to produce a complete all-in-one rabbit food. With all types of rabbit mixes, the rabbit is given a low volume, concentrated food source that satisfies all of her energy requirements. This means that there is no longer any requirement for the rabbit to spend all day grinding her teeth on fibrous material. Despite this, the teeth continue growing, resulting in overgrown teeth. Rabbit mixes increase the risk of obesity, preventing a rabbit from grooming herself properly, making it difficult for her to eat her caecotrophes. This problem is compounded by the fact that she is being over fed, so the rabbit doesn’t want to eat her caecotrophes. The uneaten caecotrophes accumulate around the anus and it is wrongly thought that the rabbit has diarrhoea.

Caecotrophes are an important source of nutrients that the affected rabbit now lacks. Add to this calcium deficiency through selective feeding and we get a rabbit that is fat, with overgrown teeth in a soft jaw bone. The affected teeth rotate within their sockets and the upper and lower teeth no longer align with each other properly. Sharp spikes then form on the teeth, and these lacerate the tongue and cheek. Approximately 50% of the UK pet rabbit population is affected by this disease syndrome to a greater or lesser extent. It is absolutely preventable, simply by feeding a diet that the rabbit is adapted to eating.

This picture shows what can happen when spurs form on the teeth.
A large laceration is clearly visible on the tongue.

Practical Feeding Advice

1. Feed grass, and lots of it. Hay is just long, dried grass, and is the ideal foodstuff for rabbits. Alfalfa hay is more expensive than most hay, is lower in fibre, and higher in calcium and protein; it is best avoided for general feeding. Timothy hay is best if it is available, but it should be of good quality (not too many seeds, no mould, slightly sweet smelling). Feed it from a hay rack, off the ground if possible, so that it is not soiled with urine or droppings. Replace with fresh hay daily, and make sure that fresh hay is always available to eat.
2. Fresh greens and other vegetables can be given as a treat. If possible, you can suspend carrots from the ceiling of the hutch to slow the rate of eating, and encourage dental exercise.
3. Small quantities of fruit are OK, but try and avoid those high in simple sugars.
4. Avoid human breakfast cereals – they are high in sugar. Sugar has severe, detrimental effects on the intestinal bacteria that are so important to the rabbit’s digestive system.
5. Avoid rabbit mixes if at all possible. In very cold weather where rabbits are housed outdoors, you can give small quantities as a supplement, but NEVER feed to satisfy the rabbit’s appetite, and always make sure that the whole ration has been eaten before giving any more if using a muesli type.