Guinea pigs are highly social animals that suffer significantly from solitary housing, yet many are still kept alone without understanding of their social needs.
Solitary guinea pigs deprived of conspecific social contact show elevated stress hormones, increased vigilance, reduced exploration, and abnormal repetitive behaviours. They are unable to engage in natural social grooming, huddling for warmth, and alarm communication. The absence of a companion significantly reduces their quality of life compared to paired animals. Social housing requires careful introduction and compatible pairing, but the welfare benefits are substantial. The Swiss legal ban on solitary housing reflects growing regulatory recognition that social housing is a welfare necessity rather than optional enhancement.