Recognizing pain in pigs is challenging because these stoic animals conceal suffering, and developing reliable pain assessment tools is critical for identifying and treating chronic pain in commercial production.
Chronic pain recognition in pigs represents one of the most significant unmet welfare needs in commercial pig farming. Because pigs evolved as prey animals and conceal weakness, the behavioral signs of chronic pain are subtle and easily missed by untrained observers. Lame sows, tail-bitten pigs, and animals recovering from painful procedures may be experiencing significant chronic suffering that goes unrecognized and untreated because the overt behavioral signals are suppressed. The development of validated pain assessment tools adapted for commercial farm use, including facial action coding systems and behavioral checklist approaches, provides farm workers with the means to identify pain that would otherwise be missed. Pain recognition training that improves worker sensitivity to subtle welfare signals is one of the most impactful training investments available for pig welfare.