Blood gases, acid-base, and metabolic alterations in calves with bronchopneumonia diagnosed via clinical signs and thoracic ultrasonography: A cross-sectional study

Background: Bronchopneumonia (BP) in calves potentially causes systemic changes. Objectives: To describe metabolic, arterial blood gas, and acid-base disorders in calves with BP diagnosed by thoracic ultrasound (TUS), Wisconsin score (WISC), and combinations of WISC and TUS. Animals: Two hundred thirty-one dairy preweaned dairy calves from 13 dairy farms. Methods: Cross-sectional study. Each calf sequentially underwent arterial blood gas evaluation, WISC score, venous sampling, and TUS. Calves were grouped based on a single diagnostic method and combination of WISC and 2 TUS cutoffs (>= 1 cm; >= 3 cm) as healthy, upper respiratory tract infection, subclinical BP, and clinical BP. Results: Oxygenation and acid-base variables were unaffected. Glucose concentration in TUS-affected calves was significantly lower (P < .001) than in healthy calves (median >= TUS1cm = 5.2 mmol/L 25%-75% interquartile range [IQR] 4.5-6.1, Conclusions and Clinical Importance: Clinical signs indicate minor systemic disorders compared to TUS. The abnormalities detected by ultrasonographic examination were moderate and did not deviate from normal reference ranges.