Guinea pigs are highly social animals that suffer significantly when kept alone. Understanding their social needs and providing appropriate housing is fundamental to their welfare.
Guinea pig welfare depends fundamentally on social companionship - a lone guinea pig is a suffering guinea pig regardless of how much individual attention it receives from humans. Their communication and social behaviours are species-specific and cannot be replicated by human contact. The minimum space requirements sold with most pet shop cages are woefully inadequate - a standard pet shop cage allows space equivalent to a small filing cabinet. Welfare-appropriate guinea pig keeping requires bonded pairs or groups in large C&C (coroplast and cubes) enclosures with enrichment, appropriate hay provision and regular social interaction.