Livestock animals actively conceal pain as prey species, creating an assessment gap that validated pain recognition tools are beginning to address across cattle, sheep, and pigs.
The systematic underestimation of livestock pain has profound welfare implications because unrecognised pain is untreated pain. Traditional stockmanship relied on gross behavioural changes that represent severe or acute pain, missing the subtler indicators of moderate or chronic pain that validated assessment tools can detect. Grimace scales, which assess changes in facial muscle tension around the eyes, nose, cheeks, and ears, have transformed pain assessment by providing objective, learnable criteria that do not require extensive veterinary training. Implementation of these tools in commercial livestock settings remains limited, partly due to awareness gaps and partly due to the perceived cost of action once pain is identified. Regulatory requirements to provide analgesia for known painful procedures are also still poorly enforced in many jurisdictions, meaning recognised pain is sometimes still untreated.