Research overview: social stress and resource competition in multi-cat households

Domestic cats are facultatively social and did not evolve to share territory with unrelated individuals, so multi-cat households can generate chronic social stress that manifests as behaviour and health problems. This overview surveys research on feline social behaviour in confined groups, the role of resource competition over food, water, litter trays, resting sites and vertical space, and how inter-cat tension contributes to house-soiling, over-grooming, aggression and stress-linked illness such as cystitis. It discusses the five-pillar environmental framework, providing plentiful, separated resources, vertical territory and escape routes, and recognising subtle signs of conflict. It also considers introductions and compatibility. The synthesis frames managing the social environment as central to welfare wherever multiple cats are housed together.