New to guinea pigs? Cage size, diet, hay, vitamin C, bonding, vet costs, and the rookie mistakes that quietly shorten their lives.
Guinea pigs need much more space than pet stores suggest. A single guinea pig needs at minimum 7.5 sq ft; a pair needs 10.5 sq ft. The Living World Deluxe XL is one of the best commercial options, though many owners build C&C cages for even more space.
Carefresh Bedding is the gold standard — it's 99% dust-free, absorbs 3x its weight, and controls odors for up to 10 days. Avoid cedar and pine shavings as they can cause respiratory issues.
Guinea pigs cannot manufacture their own Vitamin C (like humans!), making supplementation essential.
Daily Diet Breakdown:
Unlimited timothy hay (Kaytee Timothy Hay is excellent)
1/8 cup pellets per pig (Oxbow Essentials is commonly stocked by exotic-pet vets)
1 cup fresh vegetables per pig (bell peppers, romaine, cilantro)
Fresh water always available
Guinea pigs are herd animals and should never be kept alone. Always adopt in pairs (same sex unless you want babies). Floor time outside the cage for at least 1 hour daily builds trust.
Vitamin C deficiency (scurvy)
Upper respiratory infections
Bumblefoot (from wire cage floors)
Dental problems (provide unlimited hay!)
Hay — buy in bulk, it is the bulk of the diet and the cheapest per pound that way
Pellets — a 5 lb bag lasts a month for two pigs
Fresh vegetables — the largest recurring cost after bedding
Bedding — paper-based, changed weekly
Hay and vegetables dominate the monthly running cost for a pair
Rescue and welfare guidance commonly puts the minimum at around 7.5 square feet of floor for a single guinea pig and around 10.5 for a pair, and more is always better. Almost every cage sold in a pet shop as a guinea pig cage is below that.
Two things follow. Floor area beats levels — guinea pigs are ground animals and barely use height, unlike rats. And guinea pigs must never be kept alone, so you are always sizing for at least two.
If the cage you can afford is smaller than the animals need, the answer is a connected run or a C&C grid cage, not fewer square feet.
Guinea pigs, like humans and unlike almost every other pet, cannot synthesise vitamin C. They need it from the diet every single day.
Deficiency causes scurvy: lethargy, a rough staring coat, painful swollen joints, reluctance to move, poor wound healing and eventually death. It is entirely preventable and still turns up regularly at exotics vets.
Three practical points that matter more than the brand of pellet:
Stabilised vitamin C in pellets degrades. Even the stabilised form loses potency over months, faster with heat and light. Buy a bag you will finish within a couple of months and store it sealed and cool.
Do not use drops in the water bottle. Vitamin C degrades quickly in water, and flavoured water puts many guinea pigs off drinking — which is worse than the problem it was meant to solve.
Fresh vegetables are the reliable daily source. Bell pepper is unusually high in vitamin C and most guinea pigs love it.
Unlimited grass hay should be the great majority of what a guinea pig eats, every day, for life. Pellets are a supplement to hay, not the other way round.
Two reasons, both serious. Guinea pigs have continuously growing teeth, and hours a day grinding abrasive long-strand hay is what wears them at the rate they grow — without enough, molars form sharp spurs that cut the cheek and tongue. And guinea pig digestion depends on a constant flow of long-strand fibre; when that stops, the gut slows.
Timothy hay for adults. Alfalfa is a legume hay much higher in calcium, right for growing, pregnant or nursing pigs and associated with bladder stones as an adult staple.
Guinea pigs are prey animals and hide illness until they are genuinely unwell. By the time a guinea pig looks ill, it has usually been ill for a while.
Go to an exotics-experienced vet promptly for: not eating, or eating noticeably less; fewer, smaller or absent droppings; laboured or noisy breathing, or discharge from nose or eyes; a hunched posture; dragging hind legs; crusty eyes; sudden weight loss; or any lump.
Weigh your guinea pigs weekly on a digital kitchen scale and write it down. Weight loss is the earliest reliable signal you will get, and it shows up before anything visible does.
Keeping one guinea pig. They are herd animals. A single pig is a lonely pig, and loneliness in guinea pigs shows as reduced activity and appetite.
Wire or mesh flooring, which causes bumblefoot — painful ulceration of the foot pads.
Cedar or untreated pine shavings, which release aromatic oils implicated in respiratory irritation.
A rabbit as a companion. Rabbits and guinea pigs have different diets and different vitamin C needs, and a rabbit can seriously injure a guinea pig. Keep guinea pigs with guinea pigs.
Muesli-style food mixes, which let a pig pick out the sweet fatty pieces and leave the fibre.
Sudden diet changes, which in a hindgut fermenter are dangerous. Transition over one to two weeks.
Welfare guidance commonly puts the minimum at around 7.5 square feet of floor for one guinea pig and 10.5 for a pair, and more is better. Almost every cage sold as a guinea pig cage is smaller. Floor area matters far more than levels, because guinea pigs are ground animals.
You should not. They are herd animals and a single pig is a lonely one, which shows as reduced activity and appetite. Adopt in pairs of the same sex, and never pair a guinea pig with a rabbit — different diets, different vitamin C needs, and a rabbit can seriously injure a guinea pig.
From the diet every day, because they cannot make it themselves. Fresh vegetables such as bell pepper plus fortified pellets are the reliable sources. Avoid vitamin drops in the water bottle — they degrade fast and put many pigs off drinking, and pellet vitamin C loses potency within months of opening.
Not eating, fewer or smaller droppings, laboured or noisy breathing, nasal or eye discharge, a hunched posture, dragging hind legs or sudden weight loss. Guinea pigs hide illness, so weigh them weekly on a kitchen scale — weight loss shows up before anything visible does.
Paper-based bedding or kiln-dried pine. Avoid cedar and untreated pine shavings, which release aromatic oils implicated in respiratory irritation, and never use wire or mesh flooring, which causes painful ulceration of the foot pads.