Guinea pigs are popular small pets whose welfare is frequently compromised by solitary housing, inadequate space and inappropriate diet. Understanding their social and physical needs prevents common problems.
Guinea pig welfare suffers from a combination of being treated as low-maintenance starter pets and inadequate education at point of sale. Solitary housing causes chronic loneliness in an animal whose natural life centres on group membership and constant social communication. Inadequate hay provision — hay should be the foundation of their diet — causes dental malocclusion and gastrointestinal problems. Vitamin C must be supplemented daily as guinea pigs cannot synthesise it. The housing requirements are often underestimated: two guinea pigs need at minimum a 120x60 cm enclosure with hiding places, safe exercise areas, and regular time outside the cage. Switzerland's legal requirement for companionship represents a model other countries could follow.