Guinea Pig Diet: Hay, Vitamin C and Fresh Veg
Guinea pigs cannot make their own vitamin C, which changes how you feed them.
Guinea pigs share a quirk with humans: they cannot synthesise vitamin C. Everything about their diet follows from that, plus the same continuously growing teeth every rodent has.
Hay is still the base
Unlimited grass hay — timothy, orchard or meadow — should be available at all times. It wears the teeth and keeps the gut moving. Alfalfa only for under-six-months or pregnant sows.
Vitamin C every day
- Adults need roughly 10–30 mg daily; more if unwell.
- Best sources: bell pepper (especially red), broccoli, parsley, coriander, kale.
- Vitamin C drops in the water bottle degrade within hours and put pigs off drinking — use food instead.
Daily veg
About a cup of fresh vegetables per pig per day, split across two servings. Rotate varieties. Introduce anything new slowly, one item at a time.
Pellets
An eighth of a cup a day of a plain, timothy-based guinea pig pellet. Avoid mixes with seeds, corn or coloured pieces — pigs pick out the junk and leave the rest.
Watch the weight
Weigh weekly on kitchen scales. A steady drop of more than 5% is usually the first sign of dental trouble or illness.
