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What Do Guinea Pigs Eat? NZ Diet Guide (Hay, Veg & Vitamin C)

4 June 2026

What do guinea pigs eat in NZ? Mostly hay, plus daily vitamin C–rich greens and a little pellet. Guinea pigs can't make their own vitamin C — here's the diet.

The quick answer: guinea pigs need unlimited grass hay as the bulk of their diet, a daily serving of fresh vegetables rich in vitamin C, a small measured amount of guinea-pig pellets, and fresh water always. The big one most owners miss: guinea pigs can't make their own vitamin C, so they must get it from food every day — a deficiency (scurvy) makes them seriously unwell.

The guinea pig diet, in proportion

Part of dietHow muchWhy
Grass hay (timothy, meadow, oaten)Unlimited — most of the dietWears down lifelong-growing teeth, keeps the gut moving
Fresh veg (vitamin C–rich)A daily serving, variedVitamin C they can't make themselves + variety
Guinea-pig pelletsSmall measured amountTop-up (often vitamin-C fortified); not the main meal
Treats (fruit, carrot)Tiny, occasionalHigh sugar
Fresh waterAlwaysBowl or bottle, kept clean

Vitamin C — the thing people miss

Unlike most animals, guinea pigs cannot produce vitamin C, so it must come from their daily diet. Good sources include capsicum (bell pepper), leafy greens and other vitamin-C–rich vegetables. Many guinea-pig pellets are vitamin-C fortified, but vitamin C degrades over time, so fresh veg matters. Signs of deficiency (reluctance to move, poor coat, not eating) need a vet — don't rely on this guide for diagnosis.

Hay and greens

As with rabbits, unlimited grass hay is the foundation — essential for teeth and gut health. Add a daily serving of a few washed vegetables; introduce new foods gradually and in small amounts. Avoid iceberg lettuce, mouldy food, lawn clippings, and human/processed treats.

NZ context

Buy quality grass hay and keep it dry (NZ humidity spoils hay). Guinea pigs are social — they generally need a companion — and need space and a clean hutch; see first guinea pig / rabbit setup NZ. Diet is one pillar of good welfare alongside housing and company.

Quick takeaways

  • Unlimited grass hay is the core of the diet.
  • Guinea pigs can't make vitamin C — give vitamin-C–rich veg daily.
  • Pellets are a small measured top-up, not the main meal.
  • Carrot/fruit are tiny treats only.
  • Off food or unwell? See a vet promptly.

Shop related categories at PetMall

Looking for guinea pig hay, food and supplies in New Zealand? Browse the PetMall small pet range for current options and nationwide delivery.

-> Browse Small Pet Supplies

Related reading

References

  • SPCA New Zealand, guinea pig care and diet, checked 2026-06-04: https://www.spca.nz/advice-and-welfare/
  • MPI New Zealand, animal welfare codes, checked 2026-06-04: https://www.mpi.govt.nz/animals/animal-welfare/codes/

Important notice

*General diet information for NZ pet owners. For a guinea pig that is unwell, not eating, or losing weight, contact a registered New Zealand vet immediately.*

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