Pain Management in Pigs: A Deep Welfare Guide
The Importance of Pig Pain Management
Pigs are sentient animals with a well-developed capacity for pain. For decades, pain management in commercial pig production lagged behind companion animal medicine, but evidence now shows that pigs experience pain from routine procedures, disease, and injury, and that effective analgesia improves welfare outcomes and often productivity. Legal requirements in the UK mandate pain relief for certain procedures; ethical obligations extend beyond minimum legal requirements.
Validated Pain Assessment Tools
The Porcine Grimace Scale (PGS) is a validated facial action coding tool measuring: ear position changes (pinned back), orbital tightening (narrowing of the eye), cheek tightening, and nose area tension. A composite pain score of ≥3/6 indicates clinically significant pain requiring treatment. Additional behavioural indicators: posture (hunched back, weight-shifting), reluctance to move, isolation from group, and reduced vocalisation or abnormal vocalisation patterns. Stockpersons trained in pain recognition apply these tools effectively.
Analgesic Options for Pigs
Licensed analgesics for pigs: meloxicam (injectable or oral — used for post-procedural, inflammatory, and musculoskeletal pain; excellent welfare evidence base); ketoprofen (injectable NSAID, alternative to meloxicam). Opioids have limited licensed options for pigs. Local anaesthetics (lidocaine) are increasingly used for castration, tail docking, and wound management. The cascade (prescribing unlicensed products when no licensed alternative exists) allows access to additional analgesics under veterinary prescription.
Procedural Pain Management
EU and UK regulations require pain relief for surgical castration of piglets over 7 days old. Immunological castration (Improvac vaccination) provides a non-surgical alternative eliminating castration pain entirely. Local anaesthesia for castration in younger piglets is increasingly implemented. Tooth clipping (now replaced by grinding in many countries) and tail docking cause pain and should be performed only under licence as a last resort with pain management. Farrowing sow NSAIDs (meloxicam at farrowing) improve sow welfare and piglet survival.
Systemic Illness Pain Management
Pigs with pneumonia, pleuritis, lameness, gastric ulceration, and joint infection experience significant pain. NSAID treatment alongside antibiotics improves welfare outcomes and supports recovery. Identifying pain as a component of illness management — not just treating the primary cause — is a key welfare advance. Herd health plans should include explicit pain management protocols for common disease conditions, ensuring consistent treatment across the herd.