Small herbivores like bunnies have a very different digestive system to ours – which isn’t surprising as they need to digest all that grass! In this blog, we’ll describe how the herbivore gut works and explain how best to look after your bunny’s digestive health.

Herbivore diets

Herbivores are adapted to eat only vegetation. This high-fibre diet would be pretty indigestible for us humans, but herbivores have an incredibly specialised digestive tract that can extract nutrients and energy from this food.

Rabbit food in the wild is mostly grass, with a few other plants such as clover thrown in. Guinea pigs enjoy a similar menu, while other herbivores such as degus eat grasses and leaves as well as some seeds.

How is the rabbit digestive system special?

In order to gain enough energy from their plant-based diet, herbivores must keep eating for a large amount of the day. This means that their teeth will continually be munching on tough vegetation. The constant chewing wears the teeth down, and so herbivore teeth are ‘open-rooted’ – meaning they continually grow to make up for this wear.

The teeth are the first special thing about the herbivore digestive system, but it doesn’t stop there. While the oesophagus, stomach and small intestine aren’t a million miles away from ours, it’s the latter part of the rabbit digestive tract where it really gets interesting.
Rabbits are hind-gut fermenters, which means that they have a huge organ called the caecum that contains lots of microbes to break down the tough fibre in their diet. The caecum is a blind-ending sac at the start of the large intestine – we actually have one too, though ours is tiny and doesn’t do very much!

While the caecum is great at fermenting fibre, it’s not so good as absorbing all the products of fermentation. Some of these, such as amino acids and vitamins, can only be absorbed earlier in the digestive tract. To deal with this problem, rabbits have developed an adaptation that’s both ingenious and disgusting.

What they do is produce a special type of poo – little pellets called ‘caecotrophs’ – that contain the useful nutrients from the caecum. They then eat these caecotrophs and absorb the nutrients on the second time round. Rabbits tend to produce caecotrophs at night, while they’ll produce normal poo in the day when they’re feeding. The normal poo contains indigestible fibre that there’s no point eating again!

caecotrophs rabbit poo

How to support a healthy rabbit digestive system

So, now we know how special the herbivore digestive system is, how can we make sure to keep it healthy? The answer is to feed the right diet and to pick up on any problems quickly.

When it comes to herbivore diets, the secret is to base them on what the animal would eat in the wild. Most importantly, this means they should contain loads of fibre. As we’ve explained above, fibre is important for healthy digestion and for wearing down those herbivore teeth. A low-fibre diet can therefore lead to digestive and dental problems.

To make sure your herbivore friend gets enough fibre, we advise that 80% of their diet should be hay or grass. Different types of hay vary in terms of their taste and nutritional content, and rabbits can often be picky, preferring the higher quality options! Timothy Hay such as our Science Selective Timothy Hay and Meadow hay such as our Russel Rabbit Tasty Hay are both nutritious choices that bunnies love.

As well as hay, herbivores should get a portion of fresh veg and some high-quality species-specific pet food each day. This food should also contain loads of healthy fibre and not be too high in sugars. There are various different diet types available, from muesli-style mixes like our Tiny Friends Farm range to extruded diets such as our Science Selective range. If you’re interested to find out more about the different types of food available for your furry friend, check out our blog.

Rabbit infographic depicting portion sizes

How to identify rabbit digestive system problems

As well as feeding your pet the right diet, it’s important to keep a close eye out for any signs that might suggest their digestive system isn’t working the way it should be. Obviously, loose faeces or diarrhoea might indicate that something’s wrong, and if you see these symptoms then it’s best to give your vet a call.

Another sign to look out for is if your bunny goes off their food. Herbivore digestive systems are as delicate as they are complicated, and they don’t cope well with a lack of food input. If small herbivores stop eating they can become very ill very quickly, so if your furry friend stops munching it’s important to get veterinary help as soon as possible. They may need supportive feeding to get them on the road to recovery.

Finally, there are a few reasons why herbivores may stop eating their caecotrophs, and this can also put a spanner in their delicate internal works. Rabbits with arthritis or obesity may struggle to reach their back end, meaning that they won’t be able to eat the nutritious pellets. It’s important to spot this quickly for two reasons – firstly so you can identify and correct the underlying problem, and secondly so you can keep their back end clean and reduce the risk of sores or flystrike developing.

If you keep an eye out for these problems, as well as feeding your furry friend a good diet, you’ll be doing a great job to keep them healthy and happy.

Syringe feeding rabbit