Guinea pigs are social rodents whose welfare is frequently compromised by inappropriate housing and solitary keeping; they require companions and appropriate space.
Guinea pig welfare is systematically compromised in the commercial pet industry. Most cages sold alongside guinea pigs are far too small — the space requirement for a pair is at least 1 square meter of accessible floor area, far more than typical commercial enclosures provide. Solitary housing is a serious welfare problem for obligate social animals — single guinea pigs show chronic stress and reduced lifespan. Switzerland has banned solitary keeping, recognizing the welfare science. Vitamin C deficiency from inadequate fresh vegetable provision causes scurvy — painful joint inflammation and subcutaneous hemorrhage — in animals not given appropriate diet. Predator housing (proximity to cats, dogs, or rabbits) causes chronic fear stress. Simple management changes — appropriate space, pair keeping, fresh vegetables — transform guinea pig welfare.