Cats are not naturally social in the way dogs are, and multi-cat households are a leading source of chronic stress and welfare problems for companion cats — often unrecognised by owners who interpret the apparent coexistence as harmony.
The welfare problems of multi-cat households are among the most common and least recognised in companion animal medicine. Owners who see two cats occupying the same space without fighting often conclude that their cats are getting along fine — but the science of feline social behaviour reveals a much more complex picture. Chronic low-level stress from resource competition, spatial restriction, and social tension causes real physiological harm — most measurably through the stress-cystitis pathway that causes genuine urinary pain. The suffering involved is not visible as dramatic behavioural conflict but as a persistent background state of alertness and unease. Recognising and addressing multi-cat household stress is therefore a high-impact welfare intervention that requires changing owner understanding of what cat harmony actually looks like.