Pain Recognition in Pigs: Improving On-Farm Assessment

How farmers and vets can better identify pain in pigs, a species whose stoic nature and commercial environment make pain underdetection a significant welfare problem.

Key Facts

Pigs have been shown to experience pain physiologically similar to humans, with comparable nociceptive pathways and stress hormone responses
Commercial environments make individual monitoring difficult; pigs that show obvious pain signs may be targeted by pen-mates
The Grimace Scale adapted for pigs identifies pain through orbital tightening, nose flattening, cheek tightening, and ear position changes
Lameness is one of the most common and painful conditions in sows, yet is frequently undertreated on commercial farms
Post-operative pain after routine procedures such as castration and tail docking is often inadequately managed despite scientific consensus on their painfulness
Training stockpeople to recognise subtle pain indicators — changes in posture, gait, feeding behaviour, and social withdrawal — substantially improves detection
EU regulations require pain relief for piglet castration in most member states, though compliance and enforcement remain inconsistent

Welfare Considerations

Pain in pigs is systematically underdiagnosed and undertreated in commercial production. Several factors compound this: pigs hide pain as a survival instinct, farm environments make individual observation difficult, and economic pressures discourage treatment of animals close to slaughter weight. The result is that many pigs with lameness, injuries, respiratory disease, or post-procedural pain receive inadequate analgesia. Standardised pain assessment tools, combined with stockperson training, have demonstrated improvements in detection rates. Veterinary engagement with pig farms — beyond routine health visits — is essential for building pain assessment competency and ensuring analgesics are available and used. Consumer demand for higher-welfare pork can drive commercial incentives for better pain management.

What You Can Do

Advocate for mandatory analgesic use for all painful on-farm procedures including castration and tail docking
Support stockperson training programmes that include specific modules on pig pain recognition
If involved in pig production, implement a pain assessment protocol and ensure appropriate medications are stocked and used
Choose pork certified by schemes that require pain relief protocols and regular veterinary oversight
Support research into validated, practical pain assessment tools designed for use in commercial pig settings