What should you feed your guinea pig?

Guinea pigs (or cavies) are cute little creatures but they are not easy to feed correctly.

The main reason is that guinea pigs are the only species, apart from humans, who require Vitamin C included in their diet.  Most other animals have a specific enzyme that enables them to make Vitamin C.

Like rabbits, Guinea Pigs are herbivores and require a high-fibre diet.  They should have grass or grass hay (e.g. meadow, timothy, fescue, oaten, pasture, paddock, or ryegrass hays) available at all times.  Lucerne or clover hay can be offered but not as the sole source of fibre as they are high in calcium and protein. Suitable grasses include clover, buffalo grass, and oat grass.  Guinea pigs also enjoy dandelion, milk thistle, and a variety of fresh herbs.

Grass and hay encourage chewing for long periods and helps to keep their teeth in good condition, which grow continuously throughout the guinea pig’s life.  The hay is best provided to them, if possible, in a hayrack attached to their cage wall.

Fresh leafy green vegetables and herbs should also be offered.  Vegetables include broccoli, cabbage, celery, endive, beet/carrot tops, brussel sprouts, zucchini, capsicum, spinach leaves, bok choy, and other Asian greens, dark-leafed lettuce varieties, fresh (uncooked) peas and stringed beans, corn and husks (sparingly as high in calcium).  Herbs include parsley, coriander, mint, dill, basil, dandelion, rocket etc.  Offer a variety of 2 or 3 different greens each day and remember to make any changes to the diet slowly to avoid gastric upset.

Guinea Pigs also require a dietary source of Vitamin C, otherwise, they will suffer from ‘scurvy’.  This is usually supplied by the fresh greens but small amounts of vitamin C-rich fruit can also be offered e.g. citrus, kiwi fruit, strawberries.

High-quality guinea pig pellets (min 16% fibre) can be offered but only in small amounts as a treat. Many commercial pellets are too high in fats and carbohydrates, low in fibre, and should not be fed ad-lib or as the sole diet. Vitamin C content also declines once the bag is opened, and is nearly completely absent 4 months after manufacture.

Pregnant cavies have a higher requirement for Vitamin C and oral supplementation may be required.

What foods shouldn’t I feed?

Foods to avoid include cereals, grains, nuts, seeds, washed or brushed potatoes, wild mushrooms and berries, onion, shallots, avocado, rhubarb, breads, biscuits, sweets, sugar, breakfast cereals, and chocolate.

Don’t feed your cavy on rabbit or rodent pellets.

Signs of Vitamin C deficiency

If your guinea pig is not fed an adequate diet, signs of Vitamin C deficiency will occur about two weeks after the deficiency starts.  The guinea pig will be lethargic and weak.  It will eat less, lose weight, and may have enlarged limb joints.  It may develop a rough hair coat, and diarrhoea, and produces a discharge from its eye and nose.  Death usually occurs in about three to four weeks.


Guinea pigs are slobs when it comes to table manners and etiquette.  They scatter their bedding into their food, their food into their water, and their water into their bedding, and if that’s not enough they often soil in their food, water, and bedding too!

For this reason, their food and water containers must be cleaned out and re-stocked daily.

To prevent the pigs from nesting in their food and water containers, it is best if the containers are suspended above the ground.  If this is not possible, provide them with heavy food and water containers that cannot be overturned.

You will find water bottles for guinea pigs available at pet shops.  These are hygienic but guinea pigs will often block the end of the water tube with a slurry of food and water from their mouths as they drink. For this reason, their water containers must be checked daily.

Did you know that….?

  • The average life span of a guinea pig is five years.
  • Male guinea pigs are called boars, females are called sows and young are called pups
  • Length of pregnancy is 59 to 72 days – and a sow will often double her weight during pregnancy and she will produce 1 – 10 young per litter (average 3-4).
  • Piglets are weaned at around 3 weeks.
  • Guinea pigs are native to the Andes Mountains.
  • Guinea pigs are related to chinchillas and porcupines.

Adapted from Dr Julia Adams BVSc