Abstract
The aim of this study was to evaluate the serum cardiac troponin I (cTnI) concentrations in weaned calves with moderate and severe bovine respiratory disease. Eighteen healthy weaned calves (group I), 18 weaned calves with moderate bovine respiratory disease (group II) and 18 weaned calves with severe bovine respiratory disease (group III) were included in the study. Clinical signs and severity of respiratory disease according to clinical index scores were determined. Blood cell counts and cardiac biomarkers, such as serum cTnI concentrations and creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) activities were determined in all groups. Temperature and respiratory and pulse rates were significantly increased in calves with moderate and severe bovine respiratory disease compared to healthy calves (P < 0.05). Serum cTnI concentrations and LDH activities were significantly increased in the calves with severe bovine respiratory disease compared to healthy calves and calves with moderate bovine respiratory disease (P < 0.05). A significant increase in white blood cell counts in calves with moderate and severe bovine respiratory disease and lymphopenia and neutrophilia in calves with severe bovine respiratory disease were also found. The study suggests that severe bovine respiratory disease causes increased serum cTnI concentrations in weaned calves.