Guinea pigs are social animals with complex needs that are frequently misunderstood, leading to welfare problems through inadequate housing and social deprivation.
Guinea pig welfare suffers from a perfect storm of underestimated complexity: animals sold at low price points with minimal welfare guidance, housed in undersized commercial housing, and frequently kept as solitary animals. The social deprivation of lone guinea pig keeping is a significant welfare problem - these are highly social animals that in the wild live in groups and maintain constant social contact. Switzerland's legal requirement for guinea pig companionship reflects recognition of this need at policy level. The housing inadequacy problem is similar to that of rabbits - commercial hutches marketed as appropriate fall well below the space guinea pigs need to express normal locomotory behaviors. Vitamin C deficiency from inadequate dietary supplementation causes scurvy, a painful condition causing reluctance to move, mouth lesions, and hemorrhage that is entirely preventable.