Guinea pigs are highly social animals whose welfare depends on appropriate companionship, diet, and housing, with many kept in conditions that cause preventable suffering.
Guinea pig welfare failures are normalised by inadequate pet shop information: small cages, incorrect diet (often pellets with insufficient hay), and single keeping are sold alongside the animals without adequate welfare guidance. Vitamin C deficiency — preventable through fresh vegetables and hay — causes scurvy that is painful and fatal without treatment. Social isolation causes chronic stress in a species evolved for continuous group living. Welfare improvement requires better point-of-sale information, minimum housing requirements, and public education.