Recognizing and scoring pain in farmed pigs is essential for timely treatment and welfare improvement. Validated tools help stockpersons identify suffering that would otherwise go undetected.
Pain in pigs has historically been underestimated and undertreated. As prey animals, pigs suppress overt pain signs — stoic behavior has evolved to avoid drawing predator attention. This makes pain assessment challenging but not impossible. Validated grimace scales assess facial action units: orbital tightening, cheek bulging, ear position, and snout configuration reliably indicate acute pain. Composite scales combine behavior, posture, and physiological measures for broader assessment. Lameness scoring tools adapted from cattle have been validated for pigs. The critical welfare improvement is not just developing these tools but ensuring stockpersons are trained to use them and empowered to administer analgesia promptly. Farms with systematic pain assessment protocols have measurably better welfare outcomes and often better productivity.