Guinea pigs are highly social animals that suffer significantly when kept alone. Understanding their social needs is fundamental to providing good welfare for these popular companion animals.
The social needs of guinea pigs are among the most frequently neglected aspects of companion animal welfare. Despite being widely sold as starter pets or children's animals, guinea pigs have complex social, dietary, and environmental needs that are poorly served by typical small-pet care. Keeping a single guinea pig causes measurable psychological distress — the animal is deprived of social bonds that are fundamental to its species' behavioral biology. A compatible pair — same-sex pairs are easiest to manage — dramatically improves welfare outcomes. Introductions between guinea pigs require care, as incompatible animals can injure each other, but most same-sex pairs will bond successfully with appropriate introduction protocols. Additionally, guinea pigs need more space than typical commercial cages provide, access to hay at all times, and vitamin C supplementation as they cannot synthesize it. Improved public understanding of these needs would prevent significant preventable suffering.