Bovine respiratory disease (BRD) is the most economically and welfare-significant disease in the cattle industry, causing pneumonia, chronic lung damage, and death in millions of animals annually.
BRD causes acute suffering from fever, dyspnea, and the systemic effects of pneumonia. Affected calves become depressed, stop eating, and deteriorate rapidly if untreated. Chronic BRD cases that survive the acute episode may carry permanent lung damage — scarring and adhesions that limit respiratory capacity and cause ongoing discomfort during exercise. The welfare dimension of BRD is closely linked to management practices: transportation stress, mixing of unfamiliar animals, and inadequate nutrition before transit are all modifiable risk factors. Investment in pre-conditioning programs — vaccinating and adapting calves before sale and transport — significantly reduces the BRD burden and represents one of the most impactful welfare interventions in beef production.