Guinea Pig Care Guide

Guinea pigs are South American grazing rodents. They need company of their own kind and can’t make their own vitamin C. They are chatty and active at dawn and dusk, which makes them good to watch, but most don’t enjoy being picked up. They suit households that want a group of small herbivores to observe and hand-feed, and can supply fresh vegetables every day for six years or more.

Care requirements

Need	What to provide
Enclosure	Hutch at least 59 × 39 in (1.5 × 1 m) with a 79 × 39 in (2 × 1 m) run attached (PDSA). Indoors, at least 7 sq ft for one animal plus 2–4 sq ft for each extra (Merck)
Temperature	63–68°F (17–20°C) is ideal. Above 79°F (26°C) risks heatstroke and below 59°F (15°C) chills them (RSPCA)
Humidity	Dry and well ventilated, away from draughts and damp (RSPCA; PDSA)
Lighting	Normal day–night cycle, out of direct sun and away from sunny windows and radiators (RSPCA)
Diet	80–90% unlimited hay and grass, about 1 cup of vegetables per animal per day, and a small daily portion of pellets (PDSA)
Lifespan	Usually 4–8 years (PDSA)
Social needs	Groups of three or more, either single-sex or with neutered males. Never housed with rabbits (PDSA)
Legal notes	No common restrictions; check local rules.

Vitamin C, every day

Guinea pigs, like primates, can’t produce vitamin C. Without enough of it they get scurvy. VCA lists a rough coat, reluctance to walk, swollen feet or joints, and bleeding or ulcers on the gums or skin. Low vitamin C also makes them more prone to infections and dental disease. VCA puts the daily need at 10–50 mg, depending on whether the animal is young, old, stressed, healthy or pregnant.

Three things keep intake reliable:

• Fresh pellets. The vitamin C in guinea pig pellets breaks down fast. VCA says to use up or replace a bag within 90 days of its manufacture date.
• High-C vegetables in the daily cup. VCA names bell peppers, broccoli florets, cauliflower florets and parsley.
• Supplements, not water additives. If a vet recommends extra vitamin C, use tablets made for small mammals rather than dosing the water bottle.

Hay is still the base of the diet. Their teeth grow throughout life, and PDSA ties hay and grass at 80–90% of intake to correct tooth length and a healthy gut.

Housing a group

Many commercial cages are too small, especially for more than one animal. Merck’s indoor minimum is about 42 × 24 in (106 × 61 cm) for a single guinea pig. A group of three, as PDSA recommends, needs considerably more. The RSPCA asks for enough height, about 12 in (30 cm), for young animals to “popcorn”: the frisky vertical hop they do in play.

Layout matters as much as area:

• Solid floors. Grid and wire-mesh floors hurt their small feet and toes (Merck; RSPCA).
• Hiding places. Provide at least one more shelter than there are guinea pigs, plus tunnels. Merck suggests PVC pipe at least 5 in (13 cm) across.
• Deep, edible cover. PDSA recommends a 4–6 in (10–15 cm) layer of soft, dust-free hay for burrowing.
• Outdoor hutches need to be raised off the ground and weatherproof, and kept out of direct sun and wind. Bring the animals indoors when it drops below 59°F (15°C). PDSA advises moving the run often so the grass stays clean and they don’t stand in mud.

Never with rabbits

A rabbit is not a substitute for a guinea pig companion. PDSA says the two species communicate differently, need different food, and that rabbits often bully guinea pigs. Rabbits also carry Bordetella bronchiseptica, which can make guinea pigs very unwell. Merck also advises against sharing a cage because diseases can pass between the species.

Preventing birth problems

Unplanned litters are a real risk, because PDSA notes that females can conceive at three weeks old. Separate the sexes early or have males neutered. The specific danger for sows is the pelvis. VCA explains that after about 8 months of age a female’s pelvic bones become more tightly fused. A sow that has her first litter after that age is more likely to have trouble passing her naturally large pups (dystocia). VCA adds that a pregnancy running past 70 days (the average is 63) needs a vet immediately. Large litters and poor nutrition in pregnancy also raise the risk of pregnancy toxaemia, a metabolic disorder that progresses from loss of appetite to seizures and coma (VCA). Avoiding accidental pregnancy is the simplest prevention.

Gotchas

• One guinea pig “because it will bond with me”. A lone guinea pig is under-socialised. PDSA’s minimum is a group of three.
• Keeping them in a warm conservatory or near a radiator. Heatstroke can start above 79°F (26°C). An outdoor hutch in full summer sun is just as dangerous.
• Using pellets from an old bag. By the time the bag is three months past its manufacture date, much of the vitamin C may be gone.
• Mixing the sexes “until they’re older”. By three weeks it may already be too late, and a first pregnancy after about 8 months carries a higher risk of a difficult birth.
• Lifting them high off the ground. A struggling guinea pig can jump, and PDSA notes they have delicate spines. Hold them low and close to your body.

Avoid

• Cedar and raw pine shavings, whose oils irritate the lungs (Merck). The RSPCA advises against softwood bedding such as pine altogether.
• Sawdust and cat litter (Merck)
• “Fluffy” cotton-wool-style nesting, which tangles limbs, and coarse straw, which can cause eye injuries (RSPCA)
• Exercise wheels, which Merck says can injure guinea pigs
• Plastic toys that can be chewed and swallowed (RSPCA)
• Vitamin C added to drinking water (VCA)
• Housing with rabbits, or near dogs, cats and ferrets they see as threats