What do guinea pigs eat? Hay first, and vegetables every day

Hay provides the fibre a guinea pig’s gut needs to keep working, and chewing it wears down their constantly growing teeth. According to the MSD Veterinary Manual, too little fibre, or too many pellets and too much sugar, can slow or even stop the gut, causing bloating, pain and loss of appetite.

Choose a grass hay (Timothy hay, meadow hay) that isn’t dusty. Alfalfa hay is too rich in calcium and is reserved for growing youngsters and pregnant or nursing sows: the PDSA advises against it after 6 months of age.

• Put it in a hay rack or a clean, dry corner, low down rather than at eye level, to reduce the risk of eye injuries.
• Fresh grass can complement hay, but never lawnmower clippings: they ferment quickly and make guinea pigs ill.

The PDSA recommends about a cupful of vegetables, leafy greens and herbs per guinea pig per day, choosing 5 or 6 different kinds, some of them rich in vitamin C.

Every day

Peppers, celery, cucumber, romaine or leafy lettuce, carrot tops, fresh herbs.

A few times a week

Parsley, kale, spinach, broccoli: high in calcium or gassy, so give them in small amounts.

As a treat only

A little carrot or fruit (a piece of apple without the pips, or pear): too sugary to give every day.

Remove any uneaten vegetables after a few hours, before they spoil.

• Choose grass-based guinea pig pellets that are high in fibre and fortified with vitamin C, and feed the amount recommended by the manufacturer or your vet.
• Serve a fresh portion every day rather than topping up yesterday’s bowl: vitamin C breaks down once exposed to air.
• Avoid muesli-style mixes: guinea pigs pick out the bits they like best, according to the PDSA, and the Royal Veterinary College links too much dry food with dental disease.
• A youngster, a pregnant or nursing sow, or an underweight guinea pig may need a larger portion: ask your vet.

Without water, a guinea pig quickly becomes seriously ill. According to the MSD manual, a bottle fixed at the right height stays cleaner than a bowl; clean it and change the water every day, check that it flows and, in winter, that it hasn’t frozen. Don’t add anything to the water.

• Potatoes and potato peel, onion, garlic, chives, mushrooms, avocado, rhubarb, tomato leaves and stems, apple pips.
• Iceberg lettuce: mostly water, with no real nutritional value.
• Sugary shop-bought treats, honey sticks and coloured mixes.
• Plants picked from roadsides, from areas treated with chemicals or from places dogs visit.
• Rabbit pellets: not enough vitamin C for a guinea pig.

Guinea pigs often stick to the eating habits they picked up when young. For a new arrival, keep to their usual diet at first, then introduce each new food gradually over several days. A sudden change can cause serious digestive problems.

In MyArk, whoever serves the meal taps once: everyone in the household can see that your guinea pigs have had their vegetables and fresh pellets, at what time and from whom.

• One tap per meal, with the time and who gave it
• Today’s status on the Home Screen widget
• The weight chart alongside, to check they’re eating well
• The shared care log, to split the chores