Guinea pigs are popular companion animals whose welfare is frequently compromised by solitary housing, inadequate diet lacking vitamin C, and enclosures too small to allow the locomotor behavior these active social animals require.
Guinea pig welfare failures are common and often invisible because these prey animals hide illness effectively and owners may not recognize behavioral indicators of welfare compromise. Solitary housing causes chronic stress — guinea pigs vocalize for companionship and show behavioral indicators of anxiety when alone. Vitamin C deficiency causes pain from joint inflammation and poor wound healing before becoming clinically obvious. Dental disease causes progressive inability to eat, leading to weight loss and starvation if undetected. The common cage sizes sold in pet stores are inadequate — guinea pigs need space to run, and the figure-8 locomotor patterns they show in appropriate space are absent in undersized enclosures. Welfare improvement requires appropriate social housing, daily vitamin C provision, dental monitoring, and adequate space.