Measurement of serum procalcitonin concentrations in calves with bovine respiratory disease

Bovine respiratory disease (BRD) is an important and complex disease caused by various pathogens and stressors. Although BRD is often caused by viruses, secondary bacterial infections can worsen symptoms and prognosis. Due to this viral-bacterial synergy, the evaluation of bacterial infections in BRD is important for the diagnosis and prognosis of BRD. In this study, we analyzed the serum concentrations of procalcitonin (PCT), a biomarker of bacterial infection, in 41 calves with BRD. We demonstrate that when calves are categorized into PCT-positive and PCT-negative groups based on serum PCT concentrations, the PCT-positive group shows more persistently high BRD scores. These findings suggest that the measurement of serum PCT is potentially useful for the diagnosis and prognosis of calves with BRD.