Farmed Pig Pain Recognition: Grimace Scales and Behavioural Indicators

Recognising pain in pigs is essential for timely treatment and welfare monitoring. Evidence-based pain recognition tools are now available for farm use.

Key Facts

The Pig Grimace Scale (PGS) uses facial action units to assess acute pain in piglets after castration
Key grimace indicators in pigs include orbital tightening, nose bulging, cheek tightening, and ear position changes
Behavioural indicators of chronic pain include reduced activity, hunched posture, teeth grinding and tail position
Pain recognition training for stockpeople significantly improves timely intervention and pain relief administration
Validated pain assessment tools allow objective comparison of pain management protocols
Post-operative pain in pigs is frequently undertreated - assessments show inadequate analgesia in many commercial operations
The development of pig pain assessment tools follows similar work in horses, cattle and sheep

Welfare Considerations

Pain recognition is the prerequisite for pain treatment. Stockpeople who cannot reliably identify pain in pigs cannot provide timely analgesia - meaning animals experience avoidable pain for extended periods following routine procedures and in disease states. Training in grimace scale use and behavioural pain indicators significantly improves welfare outcomes by enabling earlier intervention. The validation of species-specific pain assessment tools represents genuine welfare science progress that translates directly to farm practice improvement.

What You Can Do

Advocate for mandatory pain recognition training in stockpersonship qualifications and farm assurance auditing
Support research organisations developing and validating pain assessment tools for farm species
Ask your food producers what pain assessment protocols stockpeople use on their farms
Support the Farm Animal Welfare Council's work on pain management standards in livestock production