Spay and neuter surgery is widely promoted for population control and health benefits, but emerging research on timing and individual health effects is adding nuance to blanket recommendations.
Spay-neuter decisions involve genuine welfare tradeoffs that vary by species, breed, and individual circumstances. For cats, the welfare case for early neutering is strong given overpopulation consequences. For large and giant breed dogs, emerging evidence supports delaying neutering until skeletal maturity. Individual veterinary consultation based on current evidence provides better welfare outcomes than blanket early neutering policies.