Like rabbits, Guinea Pigs are herbivores and require a high fibre diet. They should have grass or grass hay (e.g. meadow, timothy, oaten, pasture, paddock or ryegrass hays) available at all times. Lucerne or clover hay should not be offered as they are too high in calcium and protein.
Hay also encourages chewing for long periods of time 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, spinach leaves, bok choy & other Asian greens, dark-leafed lettuce varieties. Herbs include parsley, coriander, mint, dill, basil, dandelion 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, and 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.
Pregnant cavies have a higher requirement for Vit C and oral supplementation may be required - contact your vet for advice.
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