Enrichment science for companion dogs has advanced significantly, moving beyond simple toy provision to evidence-based programmes addressing sensory, cognitive, social, and foraging needs. Dogs evolved as high-activity, socially complex animals requiring mental and physical stimulation for wellbeing. Research demonstrates enrichment reduces stereotypic behaviour, fear responses, and inter-dog aggression in shelter environments. Foraging enrichment (puzzle feeders, scatter feeding, sniff walks) is particularly effective, engaging olfactory processing. Cognitive enrichment including novel problem-solving and learning activities delays cognitive dysfunction in aging dogs. Sniff walks allow dogs to follow their nose and show equivalent exercise benefit to physical activity at reduced distance. Evidence-based protocols are being integrated into shelter management and owner education.