The RSPCA’s guidance describes guinea pigs as animals with clear needs for space, company, hiding places and a carefully managed diet. This guide summarises the charity’s advice on housing, companionship and feeding. It is general welfare information, not veterinary advice. For a wider overview, see the site’s guide to caring for guinea pigs and hamsters.
Space and shelter
The RSPCA says a guinea pig needs a secure space large enough to exercise in and high enough to stand fully upright on its back legs. Youngsters are especially playful and need a height of around 30cm for their “frisky hop”, also called popcorning. Accommodation should have a solid floor with a good depth of litter, because grid floors let litter through and can hurt guinea pigs’ feet.
Guinea pigs feel vulnerable in unprotected open spaces and like to stay in contact with solid surfaces, so the charity recommends a large exercise area with secure shelter, such as purpose-made houses, cardboard boxes or tubes. The RSPCA also suggests free access to an exercise area with pipes and shelters.
Indoors, outdoors and temperature
For indoor housing, the RSPCA advises well-ventilated, dry accommodation away from direct heat sources such as radiators or sunny windows, and away from draughts. It gives 17 to 20 degrees Celsius as an ideal room temperature and warns that some areas of centrally heated houses may get too hot.
Outdoors, the hutch should be sheltered from direct sun and direct wind, with sufficient bedding throughout to keep the animals warm. The charity says that temperatures above 26 degrees Celsius can cause heatstroke, and that guinea pigs should be moved indoors when temperatures fall below 15 degrees Celsius, at which they can become chilled.
Bedding, litter and cleaning
- Bedding. Warm bedding should be safe to eat, such as dust-free hay. Softwood products such as pine can cause illness, and stranded nesting materials such as cotton wool or fluffy bedding pose a serious risk because animals can become tangled and cannot safely eat them. Coarse materials such as straw should be avoided because they can cause eye injuries.
- Litter. The RSPCA calls dry, dust-free, absorbent wood shavings, supplemented with hay for tunnelling and hiding, the best type. Wood wool is also good for hiding in.
- Cleaning. On average, the RSPCA says, accommodation should be deep cleaned at least once a week, with daily spot cleaning, but not so often that the animals are frequently disturbed.
- Gnawing. Because incisor teeth grow continually, the RSPCA recommends untreated wooden toys, pieces of fruit tree or willow sticks. It advises avoiding plastic toys, which may harm a guinea pig if chewed or swallowed.
Company: why guinea pigs should not live alone
The RSPCA advises keeping a guinea pig with at least one other friendly guinea pig, unless a vet or clinical animal behaviourist advises otherwise. Left alone for long periods, guinea pigs can develop abnormal behaviour and may suffer. The charity lists good combinations as a neutered male with one or more females, two females, or brothers reared together. Unrelated males can be introduced, but it can be tricky and may take a few attempts. Success, it says, depends more on individual personalities than on sex, and neutering does not resolve fighting. Males kept with females should always be neutered, and a vet advises on this.
New animals should be introduced gradually and under supervision, preferably somewhere new to both. Guinea pigs need places where they can escape from companions and enough resources for all of them. The charity says refuges should exceed the number of animals by one, otherwise they can become stressed and lower-ranking individuals may be bullied.
The RSPCA also says rabbits and guinea pigs do not make ideal companions and that rabbits are best kept with rabbits and guinea pigs with guinea pigs, because their needs, diets and communication differ and rabbits may bully or injure guinea pigs. The site’s guide to rabbit housing and companionship covers the other side of that pairing.
What guinea pigs eat
According to the RSPCA, good-quality hay should make up the majority of the diet and be available at all times, with fresh grass ideally every day. Hay and grass matter for the digestive system and for wearing down teeth that keep growing, and the wrong diet can cause serious dental disease. Lawnmower clippings should never be fed because they upset the digestive system.
A fresh portion of grass-based guinea pig pellets should be offered daily following the manufacturer’s instructions, because it supplies vitamin C, which is destroyed over time and more quickly with exposure to air. The charity says not to simply top up the bowl.
The RSPCA groups vegetables into three lists, each described as examples:
- Can eat often: parsley, celery, bell peppers, cucumber, gem lettuce and romaine lettuce, rotated daily.
- As a treat, a few times a week in small amounts: broccoli, spinach, kale, small pieces of carrot and a quarter of an apple, because of their sugar or calcium content.
- Cannot eat: iceberg lettuce, potato, garlic, avocado, coconut and citrus fruits.
Fresh, clean drinking water must be available continuously, checked twice daily and protected from freezing. New foods should be introduced gradually, and quantities adjusted so a guinea pig does not become under- or overweight.
Frequently asked questions
Can a single guinea pig be happy with human company alone?
The RSPCA advises keeping guinea pigs in company with their own kind. If one has to be kept alone, it says, daily interaction is vital.
The bottom line
The RSPCA’s guidance points to the same essentials: a roomy, ventilated home with hiding places and a solid floor, careful temperature control, safe bedding, a companion guinea pig and a diet built on hay, grass and a fresh daily portion of pellets with suitable vegetables. The RSPCA advises consulting a vet immediately about any change in eating, drinking or toilet habits.