Validated pain assessment tools for pigs are transforming the ability of farmers and veterinarians to identify and treat pain promptly, reducing suffering in one of the most numerous farm animal species.
Pain assessment in pigs is a welfare capability that has undergone significant development. The grimace scale approach — validated in multiple species using facial action units that change during pain — provides a simple, reliable tool that trained observers can use without specialized equipment. Combining grimace scales with behavioral indicators gives farmers and veterinarians a comprehensive pain assessment toolkit that enables more consistent early identification. Training programs that use photographic pain reference materials with pre- and post-treatment comparisons have demonstrated effectiveness in changing farmer detection and treatment behavior. The welfare dividend from improved pain detection and treatment is immediate and measurable.