Sheep are particularly stoic in expressing pain due to evolutionary pressure as prey animals, making welfare assessment and appropriate treatment challenging.
Pain in sheep is systematically underrecognized and undertreated due to the species' evolutionary tendency to minimize behavioral pain expression. Validated facial pain scales provide an objective tool for pain assessment but are not widely used in farm practice. Routine husbandry procedures including castration, tail docking, and disbudding cause pain that is frequently managed inadequately. Analgesic provision for castration is legally required only in older lambs in the UK. Lameness is the most significant ongoing welfare problem in sheep flocks, causing chronic pain that reduces grazing, body condition, and reproductive performance. Implementing systematic pain assessment and treatment protocols in sheep flocks represents one of the most impactful welfare improvements available to the sheep sector.