Bovine respiratory disease is the most costly disease in cattle production and one of the most significant welfare concerns, affecting animals from weaning through finishing.
Bovine respiratory disease represents a welfare failure that compounds over multiple stages of production. Stress at weaning compromises immunity; transport stress further suppresses immune function; feedlot mixing with unfamiliar animals adds social stress; and the resulting disease causes fever, pain, and respiratory distress. Subclinical BRD — measurable at slaughter through lung lesion scoring — causes welfare harm that is invisible during the animal life because clinical signs are absent. Prevention through minimising stressful transitions, strategic vaccination, adequate nutrition, and good ventilation reduces both clinical disease and the invisible burden of subclinical infection. Treatment with appropriate antibiotics when clinical disease occurs remains important for welfare outcomes.