Sheep are stoic animals that hide pain signs effectively. Developing reliable pain assessment tools is essential for improving welfare response to disease and injury in sheep production.
Pain recognition in sheep is systematically poor due to their evolutionary tendency to mask pain signs. Unlike cattle or horses that may show obvious lameness or behavioral change, sheep often continue eating and moving despite significant pain. This stoicism leads to undertreatment of painful conditions including foot rot, mastitis, and castration. The Sheep Pain Facial Action Unit system — a validated tool identifying pain through ear, eye, cheek, and lip muscle positions — allows trained observers to detect pain that behavioral observation alone would miss. Training farmers and veterinarians in these tools, combined with clear protocols for analgesic use, would significantly improve pain management across the global sheep population.