Guinea pigs are herbivores and originate from the Andes mountain range in South America. In the wild they forage on grass, vegetables, crops and plant matter. Like humans, guinea pigs cannot make their own vitamin C, therefore this must be provided in their diet. Commercial guinea pig feeds are available but they must be as fresh as possible as the vitamin C can break down in a matter of weeks. If a deficiency in vitamin C occurs, this can lead to scurvy. Vitamin C supplements can be given if the guinea pig becomes deficient. Vitamin A is also a requirement for guinea pig nutrition therefore must also be added to commercial guinea pig foods. Do not feed rabbit food to a guinea pig, as they do not have the same nutritional requirements.
High levels of fibre are important and can be found in fresh, good quality, hay which should be kept separate from their bedding. As guinea pigs have teeth which grow continuously, the hay can be good for grinding these down.
Vegetables and greens should make up around 10-15% of their diet. Good foods to feed guinea pigs are:
- Spinach (small amounts)
- Red or green bell peppers
- Dandelion greens (no pesticides, fertilisers or herbicides).
Foods that should be avoided are:
- Tomato leaves
Guinea pigs can be given small amounts of fruit but they can become very greedy and are prone to obesity, so they should be monitored closely. Suitable fruit are small amounts of apple, strawberry or pear. Any food given should be low in calcium as too much can cause urinary problems in guinea pigs. New foods should be introduced slowly over the course of a week if not longer. It is also natural for guinea pigs to eat their own faeces both in the wild and captivity.
Fresh, clean drinking water should be available at all times and can be offered in an animal drinking bottle. As they are social animals, they should be kept in groups with more than one drinking bottle.