Hay for rabbits and guinea pigs
Hay should be the largest part of a rabbit or guinea pig's daily diet, well ahead of pellets, because both species have teeth that grow continuously and a gut that relies on near-constant grazing to keep working properly. Unlimited, good-quality hay matters more to their health than any other single thing in the cage.
Why hay matters more than pellets
A rabbit or guinea pig's teeth never stop growing, and chewing through the tough, fibrous strands of hay is what wears them down naturally. Without enough hay, teeth can overgrow and cause real pain and feeding problems, which is a much more serious issue than most owners expect from something as ordinary as hay.
Hay also keeps the gut moving through constant, small amounts of fibre passing through, which is closer to how these species would naturally graze all day rather than eating one or two larger meals. Welfare organisations including the Rabbit Welfare Association & Fund recommend rabbits have constant access to hay roughly equal to their own body size every day.
The types in this range
Timothy hay is the most commonly recommended everyday option — lower in calcium and protein than some alternatives, which suits an adult rabbit or guinea pig that doesn't need the extra nutrients a growing or pregnant animal would. Meadow hay is a softer, more varied mix of grasses, which some animals prefer for texture and taste.
Long-stem and marigold-enriched hays add variety and encourage foraging behaviour, since a rabbit or guinea pig picking through longer strands is doing more natural, occupying behaviour than eating from a compressed block.
Storage and freshness
Keep hay somewhere dry and well ventilated rather than sealed in an airtight container, since trapped moisture causes mould far faster than open air storage does. Mouldy hay should be thrown out entirely rather than picked through, since mould isn't always visible in every strand.
Buy a size that gets used up within a reasonable time for how many animals you have, since hay does lose some freshness and appeal the longer a bag sits open, even when stored correctly.
Common questions
- How much hay does a rabbit actually need each day?
- Welfare guidance from organisations like the Rabbit Welfare Association & Fund generally recommends a body-sized portion of hay, available constantly rather than as a single measured feed, alongside a smaller amount of pellets and fresh greens.
- What's the difference between Timothy and meadow hay?
- Timothy hay is lower in calcium and protein and is generally recommended as the everyday staple for an adult rabbit or guinea pig, while meadow hay is a softer mix of grasses that some animals find more appealing for variety.
- Can I store hay in a sealed plastic container?
- It's better kept somewhere dry with airflow rather than sealed airtight, since trapped moisture in a sealed container encourages mould far more than open, ventilated storage.
- My guinea pig barely touches the hay and prefers pellets — is that a problem?
- Yes, worth addressing rather than leaving, since hay is meant to be the main part of the diet for dental and digestive health. Try a different type of hay for texture or taste, and if the preference for pellets persists, mention it to your vet.
Related
Sources
Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.
Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.