Bugs Bunny may be a fan of nothing but carrots, but did you know that real-life rabbit diets are actually far more complicated? If you are considering a cuddly little bunny, this article is for you. Today we will explain the surprisingly complex biology of rabbit digestion. Discuss good and bad diets, and go over some of the issues rabbits with poor diets may have. Time to chow down!

Rabbit Digestion

It makes sense to start at the top. Looking into a rabbit’s mouth, you will see their prominent incisors that give them that classic bucktoothed appearance. These sharp teeth are used to snip off grasses and other plant material in the wild. Further back, often out of sight behind their furry cheeks, are the cheek teeth. These teeth are for grinding tough material down so it is more easily digested. Rabbit teeth grow continuously, so a rabbit must be chewing on tough material almost all day to prevent the teeth overgrowing (more on this later).

Food passes down a rabbit’s gastrointestinal system in much the same way as other mammals, until the large intestine; here, rabbits have a large sac called the caecum. Humans actually have the remnants of a caecum: the appendix. The caecum is crucial for rabbit digestion as they are hind-gut fermenters (the caecum and colon together being the “hind-gut”).

How this works is as follows. Swallowed plant material mostly passes through the GI tract to the caecum undigested. A rabbit’s caecum is full of bacteria that are experts at breaking the plants down. The material leaves the caecum and is excreted from the back-end as caecotrophs.

Caecotrophs are soft green faecal balls, packed full of highly nutritious and easily digestible material, ready to be digested in the stomach and absorbed in the small intestine! It may seem unpleasant, but by eating these caecotrophs, a rabbit can absorb much more energy from their food. It is rare to see your pet rabbit’s caecotrophs, as they are usually passed and consumed immediately. At dusk, the poo that you see in their hutch is the remaining non-digestible material that has passed through them twice!

The Perfect Diet

You may already have some idea of what you should feed your rabbit based on the above section. A pet rabbit’s diet should be as close to a wild rabbit’s diet as possible. This means grass, and lots of it! Grass is packed full of energy, and fibre that is essential for keeping their complicated digestion moving. It also is quite tough, which provides a good grinding surface for their teeth, preventing overgrowth.

Ideally, allow your rabbit to graze outside in the garden as much as you can; provided the garden is safe and secure. This also has the added benefit of encouraging exercise to prevent obesity, and access to sunlight for health and welfare. However, if your rabbit doesn’t have easy access to fresh grass, or perhaps the grass is poorer in the winter months, you can supplement it with extra hay.

Hay is dried grass, and although it loses some nutrition once dried, is almost as good at providing nutrition, fibre and toughness. Your rabbit’s diet should be 70-80% grass and hay, but never limit the amount. As we said above, rabbits should be eating almost constantly, so ensure there is easy access to grass or hay at all times.

On top of grass… 

You can feed smaller amounts of products, such as rabbit nuggets or pellets (never rabbit muesli! See below…). These are mostly fibrous and also tough, so perform the same role as grass and hay. It is best to give these in smaller quantities. Unlike grass and hay, you definitely should measure the amount you give to avoid obesity; the back of the packs usually have weight charts you can follow as good guidelines. 

Finally you can give small treats every so often…

But no more than 5-10% of their diet. Many shop-bought treats are high in sugar and quite unhealthy. Instead, ideal treats include apple, banana, green vegetables or Bugs Bunny’s favourite – carrots. All of these can still be sugary, so please give sparingly. A good tip is to give your rabbits the discarded ends of vegetables you are cooking with (and it’s good for the planet too!).

By following the above guidelines, your rabbit will be on a diet that should help keep them healthy and happy. 

However, not all rabbits are fed appropriately, and many become ill as a result. Possibly the biggest culprit behind poorly fed rabbits is rabbit muesli – muesli is made up of wheat, peas, grasses, oats, fruit, straw, beans, oil and other material. These may sound healthy and look appealing, but many of the components are high in fat and sugar, which can cause obesity. This can be exacerbated when your rabbit picks out the tasty, but unhealthy, parts and leaves behind the healthier components. Muesli is also quite soft, so does not provide a good surface for rabbit teeth to grind on – a rabbit fed on only muesli often will have overgrown teeth. Other poor quality foods, excess treats, and a lack of grass and hay, also contribute to dietary issues.

Dental Diseases

By eating soft food, a rabbit’s teeth will not be ground down sufficiently. Overgrowth teeth will start to become ineffective and not grind food properly. This speeds up the disease process, as underuse grinds them down even less. If not treated via grinding by a vet, overgrown teeth causes dental disease. Dental disease can lead to issues such as mouth abscesses, eye issues, weight loss, tooth loss, anorexia, gut stasis, bone deformities and can even be fatal in advanced cases. Prevention is so much better than the cure, so feeding lots of rough food is crucial for good dental health in rabbits.

Obesity in rabbits

Typically caused by inactivity and a high sugar diet, obesity is associated with many of the same problems other obese animals face. Obesity causes heart disease, liver disease, poor skin, mobility issues, anorexia and gut stasis, flystrike, and a reduced lifespan. You should regularly weigh your rabbit and assess how much excess fat they have – ask your vet for help with this. If you suspect your rabbit is gaining too much weight, cut down on treats and nuggets – however, never reduce their intake of healthy grass and hay as this can lead to gut stasis.

Gut stasis

We’ve mentioned gut stasis a few times now – gut stasis is where a rabbit’s digestive system shuts down. This serious condition usually requires veterinary intervention. A rabbit with gut stasis may not eat and be quiet, hunched over, may grind their teeth, and have associated obesity or dental disease – however, these signs can often be subtle or even not present in the early stages. Treatment usually involves fluid therapy, pain relief, drugs that encourage gut motility, and nursing. The prognosis is often quite poor, so avoiding gut stasis by providing a healthy diet is crucial.

If you are concerned your rabbit is on a poor diet, it is never too late to change. You shouldn’t make sudden changes however, as this shock can cause reluctance to eat and gut stasis. Instead, introduce the new diet slowly while simultaneously phasing out the old diet, over a few weeks. Again, ask your vet if you need some assistance. 

Final Thoughts

Pet rabbit diets do not have to be difficult. Consider their wild cousins and stick to a diet of all-natural grass or hay, with some added extras and treats in small quantities. Keep an eye out for signs of illness or disease that may indicate a dietary issue, and have your rabbit checked by your vet regularly – they can often spot problems early, giving you time to make changes to their diet. Follow our advice above to help ensure your rabbit stays healthy and happy for years to come.