Evidence-based care for one of the world's most popular small pet species
Guinea pigs (Cavia porcellus) are among the most popular companion animals globally, particularly for children. Yet standard pet care recommendations are often inadequate: minimum cage sizes specified by manufacturers are far below welfare-appropriate sizes; single housing is common despite guinea pigs being highly social animals; and dietary misconceptions (inadequate vitamin C, insufficient hay) cause common health problems. Evidence-based guinea pig welfare guidance can prevent significant preventable suffering.
Guinea pigs are highly social herd animals that evolved in multi-individual groups. Single housing causes chronic loneliness and psychological distress. Minimum welfare-appropriate housing is pairs or small groups of the same sex (or neutered). The bond between bonded guinea pigs is strong; separation causes measurable distress and should be avoided.
Typical pet store cages (0.2-0.4 m²) are inadequate for guinea pig welfare. Welfare-appropriate minimum: 0.7 m² for one guinea pig, 1.0+ m² for two — roughly C&C cage (2×4 grid) size. Guinea pigs should have access to outdoor time in secure runs during appropriate weather. Burrowing substrate, hiding places, and varied enrichment are essential for behavioral welfare.
Guinea pigs, unlike most mammals, cannot synthesize vitamin C and require dietary sources. Deficiency causes scurvy — a painful condition causing joint pain, bleeding gums, and weakness. Unlimited fresh hay (Timothy, meadow) is essential for dental health and gut motility. Fresh vegetables providing vitamin C daily: bell peppers, leafy greens, broccoli. Commercial guinea pig pellets supplemented by vitamin C are adequate but hay and fresh vegetables should form the majority of diet.