Validated pain assessment tools for pigs allow stockpeople and veterinarians to identify suffering that might otherwise go undetected. Using these tools consistently improves welfare outcomes at scale.
Pig pain assessment represents one of the most important frontiers in practical farm animal welfare because pigs conceal pain as an adaptive behavior in social groups. A pig that continues moving through a group and competing for food may nonetheless be experiencing significant chronic pain. The Pig Grimace Scale, validated through controlled pain studies, provides a facial action unit-based method that circumvents behavioral masking and allows direct assessment of pain state. Trained stockpeople using grimace scale scoring can identify painful individuals, prioritize treatment, and evaluate analgesic efficacy. Building pain assessment competency into routine farm management transforms reactive treatment into proactive welfare management. When combined with regular behavioral observation and health records, grimace scale data creates a comprehensive picture of pain burden across the herd.