Developing and validating pain assessment tools for pigs is essential for identifying suffering and evaluating treatment effectiveness.
Objective pain assessment in pigs is fundamental to addressing welfare problems but has historically been limited by the lack of validated tools. Pigs show subtle facial expression changes that trained observers can use to assess pain states. Combining facial expression scoring with behavioural assessment and physiological measures provides the most complete pain evaluation. Routine use of pain assessment tools by stockpeople and veterinarians enables earlier intervention and objective evaluation of analgesic effectiveness. Mandatory pain assessment training for pig handlers would improve welfare outcomes significantly.