How the timing of spay and neuter procedures affects long-term health outcomes in dogs, and the evolving evidence guiding veterinary recommendations.
Spay-neuter timing is evolving from a one-size-fits-all approach toward breed-specific, evidence-based recommendations. The welfare motivation for early neutering — preventing unwanted reproduction and certain cancers — remains valid, but evidence now shows early neutering increases joint disorder risk in large and giant breeds in ways that cause chronic pain and reduced mobility. The welfare-optimal approach balances reproductive control, cancer prevention, and musculoskeletal health through breed-appropriate timing and, increasingly, through hormone-sparing sterilisation options that prevent reproduction while preserving hormonal contributions to development.