Guinea pigs, or cavies to give them their proper name, are rodents originating from South America. They are social animals, living in family groups or small colonies. Natural habitats range from grassy and shrub-covered savannahs, to lower mountain slopes. They spend most of their day traversing grass and scrub trails whilst grazing, re-familiarising themselves with their territory (averaging 1,500 square meters), socialising, playing, and taking naps. For naps and night-time sleep they usually seek out burrows dug by other animals, rocky caves or crevices, or thick bushy or grassy clumps. These offer some protection from predators plus shade or shelter from the elements, whilst providing fairly even temperatures. Cavies do not cope well with temperature extremes, nor rapid or frequent fluctuations. The temperature range should be between 15°C / 59°F and 24°C / 75°F, with the ideal being 18°C / 64°F. Humidity levels are also important, within a range of 45 – 65%, the ideal being 50%, notably to prevent respiratory problems.
Cavies should not be kept alone unless there is an overriding medical reason to do so. The absolute minimum housing space for 2 animals is 4 square feet each (3,600 sq cm). A 3ft x 3ft cage (1-meter square) can accommodate 2 sows. Boars need more space than sows to discourage territory or resource disputes or any hormone stimulated aggression. Bigger is definitely better! Cavies (as a rule) are not climbers or jumpers thus prefer single storey accommodation with fixed solid bases (no wire bottoms). They also have very short but thin matchstick legs that break easily, so ramps with steep inclines and no sides are hazardous.
Due to the vagaries of the British climate, cavies are best kept indoors where the environment can be controlled, especially autumn through to spring when rain and temperature fluctuations predispose them to illness, or alternatively in an insulated outbuilding with some safe heat source available for cold, damp spells. Housing needs to be sited away from draughts, heat sources and direct sunlight. If kept outdoors in the summer the hutch roof will need a good overhang and to avoid exposure or heat stroke issues be sited facing away from the prevailing weather and sun. Commercial plastic type hutch coverings are not ideal – the poor ventilation afforded can predispose occupants to respiratory conditions, including pneumonia. External doors to the refuge or ‘bedroom’ area should have door jambs (as in human dwellings) to prevent draughts, with secure fastenings – preferably including a bolt, (Toggle types can come loose causing the door to flip open; hooks are easy for predators to flip off). Refuges should not be fully open to the exercise area but partitioned off by a solid internal dividing wall with a rear doorway.
Exercise and foraging areas must be available, with room for the guinea pigs to freely canter, ‘popcorn’ and explore. Each animal needs its own ‘refuge’ or roofed bed for naps or quiet retreats. Provide communal toys too such as tunnels, pods or huts of different sizes and lengths for enrichment purposes, sufficient to prevent arguments over resources, or low ranking animals being trapped between higher ranking individuals or left out and feeling ‘exposed’. Food and water stations should be sited away from refuges (bedrooms) and toileting areas. A predator-proof pen used for summer grazing needs a roof both for weather protection and to create a ‘safe zone’ and must incorporate a refuge shelter.