Rabbits are animals that basically feed on grass and shoots in the wild. Their digestive system is designed to digest these types of food effectively. The main component of this kind of food is fibre. Therefore, our pet rabbit should be fed as similarly as possible to avoid problems. Because this type of food is low in calories, rabbits eat throughout the day, more than 20 times in 24 hours, in small sessions of about 4-6 minutes. Therefore, as we will see below, it is very important that our rabbits always have food available, although the quality of that food is also important.
To understand how fundamental the rabbit’s diet is, we must understand how its digestive system works. As we have already said, the rabbit is designed to digest grass and shoots, or in other words, fibre. Therefore, their digestive system has evolved to facilitate the digestion of this type of material.
The first thing we find are the teeth of rabbits. Both incisors and molars grow continuously all life. This is because fibrous foods require a lot of chewing to facilitate their digestion (rabbits chew about 120 times per minute when they eat), but fibre is very abrasive, so the teeth wear out when chewing and hence they grow continuously. Incisors, for example, can grow up to 2 mm in a week.
If we fail to provide the rabbit with a high fibre diet, the teeth will continue growing despite not being worn out properly. This will eventually lead to severe problems like wounds inside the mouth due to dental spurs, root abscesses and anorexia, with the molars sometimes growing inside the nose or coming down the mandible branches in severe cases. If the problem is mild it could be reversed with dental trimming that would require anaesthetic, but many times the bone structure of the teeth and skull has changed and the dental problem will become chronic and potentially fatal for the rabbit.
Most carbohydrates and proteins are absorbed in the small intestine. From there, the feed progresses to the main fibre fermentation chamber, the caecum. Using a unique system in rabbits, the large intestine separates the non-fermentable part of the intestinal content, which is excreted in the faeces in the typical round pellet shape, from the fermentable part, which moves retrograde towards the caecum for fermentation. The content that enters the caecum is usually composed of fibre (70%) and nitrogenous components (15%).
The caecum is the largest part of the rabbit’s intestine. It is full of bacteria and other microorganisms that ferment food (especially fibre) to extract energy and produce proteins and vitamins. In a small sample of the caecum there are between 1010 and 1012 bacteria (100,000,000,000 bacteria). The fermentation of the fibre forms volatile fatty acids such as acetate, butyrate and propionate that provide between 30% and 50% of the basal metabolic needs of the rabbit.
It is interesting to note the low amount of short chain carbohydrates present in the caecum content, since this is a limiting factor for pathogenic bacteria. In diets that are rich in these components (with low intake of hay and high content of pellets or cereals), an imbalance occurs in the composition of intestinal bacteria, which usually leads to an overgrowth of Clostridium-type bacteria (a process called dysbiosis). This can cause from diarrhoea to a generalized intestinal stasis and septicemia, causing the death of the rabbit.
The rest of the content of the caecum, that is not absorbed, is transformed into caecotrophs that are expelled and ingested by the rabbit.
The proteins, vitamins and other nutrients derived from fermentation that are not absorbed in the caecum are transformed into a special type of stool called caecotrophs. These have a shiny appearance, accumulated in a kind of cluster, and covered with mucus.
They are normally expelled twice a day, during quiet periods, and are usually ingested directly from the anus, which is why they are rarely seen.
Caecotrophs are 34% composed of dry matter, of which 18% is fibre and 30% is protein (most of this protein being of bacterial origin), and it also contains many bacteria that will be digested later, which provides the rabbit with vitamins (thiamin, riboflavin, niacin, pantothenate, pyridoxine, folate, B12, biotin, vitamin K), essential amino acids and minerals. Thanks to the mucus coating they have, they pass through the stomach without much alteration and all the nutrients are absorbed in the small intestine.
In certain circumstances, such as in obese rabbits, in older rabbits with osteoarthritis or in animals that cannot reach the anus to consume the cecotrophs, they can develop problems due to the lack of essential components in the diet that only come from the caecotrophs.
In rabbits, intestinal motility is very important. Of course, it helps the passage of food through the digestive system and the formation of caecotrophs in the large intestine, but it also helps the passage of hairs that rabbits ingest when grooming without causing issues. In these animals, fibre in the diet is the main stimulant of intestinal motility. For this same reason, a low fibre diet will predispose the animal to problems derived from low motility. Many times the hairs accumulate in the stomach and end up forming very severe obstructions. Other times, it can cause digestive stops, partial or complete, which can lead to dysbiosis and potential septicemia. At the same time, it will reduce the rabbit’s appetite, making the situation even worse.
Now that we know how the digestion of the rabbit works, we will talk a little about how the ideal diet for a rabbit should be. We are going to talk about the diet of an adult domestic rabbit, which is not breeding. Rabbits in other stages, such as growing rabbits or pregnant females, have particular needs that we will address in other posts so as not to make this too extensive.
First, the rabbit’s diet must be designed to meet its nutritional and energy needs. But we must think that wild animals spend many hours a day looking for food, with a type of behaviour called foraging. Therefore, we must promote this type of behaviour in our animal in order to keep it entertained while feeding. If we do not do this, he will spend very little time eating and in the end he will become bored and this can lead to unwanted behaviours such as biting the bars of the cage, pulling his hair or fighting with others.
Offering the rabbit food in different areas and with different ways of access is interesting. We can hang the hay from the bars of the cage, hide the feed inside a box, mix the vegetable leaves with paper or straw so that it has to be found, among many other ideas that you can find on the internet.
The components of a typical rabbit diet are: hay/grass, vegetables (leafy) and pellets/commercial food. Remember that rabbits should always have fresh, clean water available. It is important to mention that rabbits drink more water from bowls than from bottles, although these get more dirty, and we have to clean them more often.
Hay is the most critical part of the rabbit’s diet. It is very rich in fibre and is very easy to store for long periods of time. Hay must be available to the animal at all times. We can offer it in a drawer outside the cage, in a clean corner on the floor of the cage, hanging from the ceiling or hidden inside a box for example. If the hay is used on the floor of the cage, it will have to be changed frequently since the rabbits will urinate and defecate on it, and once dirty, the rabbits will not eat it.
There are different types of hay, but they are basically divided into legume hay, such as alfalfa, and grass hay, such as rye grass or Timothy. Legume hay is good for animals with high nutritional demand, such as lactating females or growing rabbits, but it is not recommended for other animals. Grass hay is most recommended as maintenance hay, it is rich in fibre and low in energy, which helps keep weight at bay.
Fresh grass can be given as well but is more difficult to obtain. If you have access to it, remember to wash it as they can carry pesticides or parasites. They can eat as much fresh grass as they want, and they can even eat the flowers if they like it. Be sure no toxic plants are included and if you are not sure it is better not to give them.
Rabbits can consume vegetables, but they should only consume the leaves, as these provide fibre, water and minerals that are great for rabbits, but are low in carbohydrates. The leaves can be offered at any time in the rabbit’s life, but if they have never tried them before (as in the case of a rabbit that begins to eat solid food) they should be introduced gradually and carefully, always monitoring the faeces. My recommendation is to give a couple of handfuls a day of vegetable leaves, divided into two doses a day. Vegetables that have not been eaten should be removed after an hour or two because they rot quickly and become dirty.
Typical vegetables that can be offered are lettuce (not iceberg), rocket, chard, spinach (these are not recommended in animals with urinary stone problems due to their high calcium content), kale, cabbage, broccoli leaves, carrot leaves …
Non-leafy vegetables, such as carrots, peppers, cucumbers, zucchini, broccoli, etc. can be offered in small quantities and with care since they can cause digestive diseases if they are offered in large quantities.
Onions, garlic, leeks, and chives are toxic to rabbits and should not be eaten under any circumstances.
Feed is an important part of the rabbit’s diet but should be offered in small amounts. We will use the feed as a way to balance the diet with amino acids, vitamins and minerals since, since it is impossible to offer the same variety of grass and shoots that a rabbit can find in nature, our diet at home can be deficient. It is important to find a high quality feed to be sure that the nutritional contribution is adequate. Fibre values should be around 20-29%, protein values between 13-14%, calcium <1% and energy over 1.6kcal/g. Feed designed for fattening rabbits or breeding females should not be used, as their nutritional values exceed those recommended for the maintenance of a domestic rabbit. Grain and seed based mixes should not be offered as they are nutritionally deficient and too high in calories.
The feed can be offered ad libitum (freely available) in pregnant or lactating rabbits and in growing rabbits up to about 6 months. In any other case, the feed should represent a small part of the daily intake. My recommendation is between 1 and 2 tablespoons a day, depending on the size of the rabbit. But it is always important to weigh the rabbit regularly and if the weight rises, or the rabbit stops eating, we must reduce the amount of feed that we offer.
Fruits should be used carefully as they are high in sugar, so as we have seen, not good for the digestive tract of the rabbit. A small slice of fruit can be given sometimes, maybe 2-3 times a week, and will not cause much problem.
Treats are good for training and treating the rabbits but we need to be sure that they are hay or grass based or something rich in fibre. Sugary treats are to be avoided. Again, we should be careful with the amount of treats as they can lead to obesity.
As we have seen, fibre is the most significant part of a rabbit’s diet, and we have been able to see what happens if we do not offer enough of this component to our animal every day. Therefore, let us remember that 80-85% of the daily intake should be hay or grass, 10-15% leafy vegetables and 5% of good quality feed. It is interesting to assess the weight of our rabbit on a regular basis to assess whether the diet we offer is too caloric. Encouraging the rabbit to exercise with environmental enrichment and playing with it are good strategies to keep weight at bay and have a happy rabbit.
If you have any questions, you can send me a message in the contact me section at the bottom of the page and I will be happy to answer. I hope you have enjoyed the post!
