Diagnostic Utility of Ultrasonographic and Clinical Assessment of Bovine Respiratory Disease in Feedlot Calves

Abstract

Bovine Respiratory Disease (BRD) is a main cause of death in feedlot cattle, leading to considerable economic losses. This work designed to assess the clinical and ultrasonographic features of BRD-affected calves and to evaluate the risk factors associated with its development. Forty calves (3-9 months old) were selected, including 22 BRD-affected and 18 clinically healthy calves (control group). The calves were examined for clinical signs such as fever, dyspnea, nasal discharge, coughing, and weight loss. Lung auscultation revealed abnormal sounds, including wheezing, crackles, and moist rales in BRD-affected calves. Ultrasonographic examination was performed using a handheld ultrasound device, revealing hypoechoic zones, pleural thickening, and areas of consolidation in the lungs of BRD-affected calves. These results support the use of clinical lung scoring combined with lung ultrasonography for diagnosing and classifying calves based on the severity of lung lesions. Transportation and commingling of calves were identified as key predisposing factors for BRD, as stress and exposure to multiple pathogens increased disease susceptibility. This work highpoints the value of combining clinical and ultrasonographic approaches for the early diagnosis of BRD and suggests that computer-aided lung scoring systems may enhance diagnostic accuracy in feedlot settings.