Feeding Pet Guinea Pigs

A lot of medical conditions in guinea pigs begin not with disease but from an inappropriate diet, so we decided to help our lovely guinea pig owners with some advice on what to feed.

In addition to these food recommendations, fresh water should be supplied daily and ideally offered from both a bowl and a bottle.

Gut health

Guinea pigs rely on a high fibre diet to keep their guts healthy and moving. Good quality meadow hay should represent 85-90% of their diet. Large piles of fresh feeding hay encourage your guinea pigs to eat the fibre they need, while also encouraging natural burrowing and foraging behaviour.

It is completely normal and healthy for guinea pigs to eat their own poo. Their first poo is known as a caecotroph and is a soft, sticky dropping that they re-eat to get the rest of the vital nutrients from it. The second time they are digested they are excreted as hard droppings.

Dental health

Guinea pigs’ teeth grow constantly throughout their lives, and so they also rely on the fibre in hay and grass to keep their teeth worn down. If their diet doesn’t contain enough hay, their teeth can form painful spikes that prevent them from being able to eat. The importance of ad lib good quality hay as the majority of the diet cannot be emphasised enough.

Vitamin C

Just like humans, guinea pigs cannot produce vitamin C themselves and so need to get it from their food. Pelleted food designed for guinea pigs is fortified with vitamin C and around a tablespoon of pellets per day should be offered. Avoid muesli-style mixes as the guinea pigs will pick out only the bits they like best and these are often high in sugar and low in fibre.

The remaining vitamin C in their diet should come from fresh greens and vegetables – around a teacup full per day. This can include dark green cabbage, kale, chicory, watercress, rocket, spring greens, bok choy, Swiss chard, celery leaves and carrot tops. You can also offer fresh grass (not mown grass clippings), herbs and wild plants including dandelion leaves, groundsel, cow parsley, basil, sage, mint and coriander.


Fruit and root vegetables can be given infrequently, perhaps once or twice a week, in small quantities – for example apple slices (not the pips), banana, melon, carrot and parsnip. They are high in sugar and can cause weight gain if fed often.

Foods which are unsafe include potatoes and potato skins, onion, garlic, avocado and nuts and seeds. Iceberg lettuce should be avoided as it has little nutritional value and can cause diarrhoea.