Choosing the Right Hay for Guinea Pigs: Timothy, Meadow, and More

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Choosing the Right Hay for Guinea Pigs: Timothy, Meadow, and More

Unlimited grass hay should form the bulk of every adult guinea pig's diet - it wears down their constantly growing teeth and keeps the gut moving. For healthy adults, timothy or meadow hay is ideal. Save alfalfa for young, pregnant or nursing pigs, because it is too high in calcium and calories for adults. Always choose green, sweet-smelling, dust-free hay.

• Hay should be roughly 80% of a guinea pig's diet and always available.
• Constant chewing of hay wears down teeth that grow for life.
• Timothy and meadow hay suit healthy adults best.
• Alfalfa is a legume, not a grass - too rich for most adults.
• Good hay is green, smells sweet, and is free of dust and mould.

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Why hay matters so much

Guinea pigs evolved to graze on fibrous grass all day. That constant chewing does two vital jobs: it grinds down their teeth, which grow continuously and can overgrow painfully without wear, and the fibre keeps their digestive system moving. A gut that slows or stops is a genuine emergency in a guinea pig. Pellets and vegetables matter, but they cannot replace hay - a pig that fills up on pellets and skips hay risks both dental disease and dangerous gut slowdown. Hay should be available 24 hours a day.

Grass hays: timothy and meadow

For healthy adult guinea pigs, grass hays are the everyday staple. Timothy hay is the most popular: consistent, high in fibre, and moderate in protein and calcium. It comes in different cuts - earlier cuts are coarser and stalkier, later cuts softer and leafier - and many pigs enjoy a mix. Meadow hay is a blend of grasses and is often softer and more varied, which fussy eaters like. Other grass hays such as orchard grass are useful alternatives, especially if anyone in the home is sensitive to timothy dust.

Timothy and meadow hay suit adults; alfalfa is for young, pregnant or nursing pigs only.

Alfalfa and when to use it

Alfalfa is often sold alongside grass hays but it is a legume, not a grass, and it is much richer - high in calcium, protein and calories. That makes it right for guinea pigs with high demands: babies under about six months, and pregnant or nursing sows. For a healthy adult, though, everyday alfalfa can contribute to obesity and to bladder stones from the excess calcium. Use it as an occasional treat at most for adults, and switch growing pigs over to grass hay as they mature.

Judging and storing hay

Quality varies a lot between batches. Good hay is green rather than yellow, smells fresh and sweet like a summer field, and is free of dust, mould and coarse weeds. Avoid anything grey, musty, damp or very dusty, which can cause respiratory irritation - a real issue in humid Hong Kong and Taiwan homes where hay can go mouldy fast. Store hay somewhere cool, dry and airy, never sealed in plastic where moisture builds up. Buy in amounts you will use while fresh rather than one huge bale.

Good hay is green, sweet-smelling and dust-free; avoid yellow, musty or dusty batches.

Living context by region

This guide is written for multi-region English readers (US/UK/AU/NZ/CA/EU and more). Where climate, products, or vet access differ, prefer local veterinary advice and local product labels. Use metric first; keep °F/lb in mind for North American homes.

When to call your vet

• Signs are getting worse over hours, not better

• Pain, persistent vomiting/diarrhea, or neurological signs

• You needed force or guesswork to keep going at home

Common mistakes

• Waiting because the animal 'still looks okay' while prey species hide pain

• Changing five variables at once so you cannot tell what helped

• Copying drug doses from social media

• Skipping species-appropriate husbandry while buying more gadgets

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