Table 3.

Classification of clinical BRD status in feedlot cattle using a combination of visual signs detected by pen riders, veterinary treatment records, and lung and pleural lesions of the respiratory tract at slaughter

Clinical BRD status	Description
Clinical	Visual signs of BRD1, treated for BRD due to rectal temperature ≥40°C or lung auscultation ≥2, with severe lung lesions at slaughter
Subclinical	No visual signs of BRD, never treated for BRD but with severe lung lesions at slaughter
Treated with no lesions	Visual signs of BRD, treated for BRD, and with no severe lung lesions at slaughter
Visual control, treated, no lesions	No visual signs of BRD but treated for BRD due to elevated rectal temperature or lung auscultation score, with no lesions at slaughter
Healthy	No visual signs and normal rectal temperature and lung auscultation score, and normal or moderate lung lesions at slaughter

¹Visual signs, presence of one or more of the following detected by pen riders; lethargy, abnormal animal carriage, labored breathing, cough, nasal or ocular discharge, anorexia. Animals had to have one or more of the visual symptoms specific to BRD (nasal or ocular discharge, or labored breathing or cough).