In a spontaneous induction model, 11 healthy calves were exposed for 3 days to 15 multiple sourced commercial calves carrying bovine respiratory disease (BRD) viruses (2 were un-infected controls). The calves received respiratory nitric oxide gas (NO) either immediately upon exposure to the BRD carriers or upon early identification of BRD from infrared orbital scans (IRT). A third group were treated with NO upon the appearance of clinical signs. All animals treated early with NO (preventative and early detection group) displayed IRT and clinical scores (36.2 C±0.2; 2.7±0.4) similar to controls (36.3 C ±0.2; 1.4±0.5) but lower than the clinical treatment group (37.0 C±0.2; 3.9±0.4, P <0.05). The data suggest infrared thermography is able to detect signs of bovine respiratory disease earlier than conventional clinical scoring systems: nitric oxide may be an effective adjuvant in treating bovine respiratory disease.