Guinea pigs are highly social animals whose welfare is seriously compromised by solitary housing, with pair or group housing now considered the minimum standard across European countries.
Solitary guinea pig housing is a common welfare failure driven by pet industry sales practices and buyer ignorance rather than any welfare benefit of isolation. Research and legislation in Switzerland and other European countries confirms that guinea pig welfare requires conspecific companionship as a minimum standard. The obligation for the UK, US, and other countries to similarly protect guinea pig social needs through legislation is clear. Pet store practices that sell single guinea pigs without requiring companion purchase contribute to preventable welfare harm.