Cats kept exclusively indoors need carefully designed environments to express natural behaviours and maintain good psychological welfare throughout their lives.
Indoor cats are protected from road traffic, predators, and infectious disease, but face the welfare cost of restricted behavioural expression. Natural hunting, climbing, territory marking, and social interaction are curtailed. Without deliberate enrichment, cats may develop obesity, overgrooming, aggression, or urine marking. The Five Freedoms framework requires that indoor cats have freedom to express normal behaviour — this demands active owner effort.