Recognizing and treating pain in farm pigs is a fundamental welfare obligation. Advances in pain scoring tools and veterinary treatment protocols are improving outcomes for pigs in agricultural systems.
Pig pain recognition is complicated by their behavioral masking of pain signs as prey animals in the wild. Pigs experiencing significant pain may continue eating and appear superficially normal when approached by humans. The Pig Grimace Scale — using orbital tightening, cheek tightening, nose wrinkle, and ear position — provides objective coding that trained observers can apply reliably. Routine procedures including surgical castration of male piglets without analgesia cause clear physiological and behavioral pain responses that can be substantially reduced with local anesthetic and meloxicam. Lameness — which affects significant proportions of breeding sows — is frequently undertreated due to difficulty recognizing subtle gait changes in large groups. Implementing pain management as a routine part of herd health programs is the appropriate welfare standard.