The question of whether cats should be kept indoors or allowed outdoor access involves balancing welfare benefits of enrichment and freedom against significant mortality and wildlife impact risks.
The indoor-outdoor question involves genuine welfare trade-offs. Indoor-only cats in unstimulating environments frequently develop obesity, idiopathic cystitis linked to stress, over-grooming, and redirected aggression. Outdoor cats experience greater environmental enrichment and exhibit a wider range of natural behaviours, but face substantially elevated risks of traumatic injury and infectious disease from other cats. The ideal solution for most cats is enriched indoor environments combined with safe supervised outdoor access — through catios, secured garden systems, or harness walking. Cat welfare and wildlife conservation advocates now largely agree that safe outdoor access is preferable to entirely eliminating natural behaviour expression.