Lung Inflammatory Response in Neonatal Diarrheic Bovine Calves with Respiratory Disease Syndrome (RDS)

Abstract

To investigate the lung inflammatory response during diarrheic episodes in neonatal calves with respiratory disease syndrome, 27 newly born bovine Friesian calves of both sexes (up to 30 days old) were studied, of which 17 diarrheic calves with RDS admitted to the Hospital of the Faculty of Veterinary Medicine Zagazig University and ten apparently healthy calves with no history of any previous illness kept as a control group in the same age range. The examined calves were admitted with a history of diarrhea with respiratory disease syndrome and presented with a variety of clinical signs, including anorexia, diarrhea, cough, dyspnea, and variable degrees of nasal discharge dehydration, weight loss, dullness and pale mucous membranes. The laboratory findings reveal significant changes in diarrheic calf blood parameters, with the RDS group showing significantly lower pH, PaO₂, HCO₃, BE, and significantly higher PaCO₂ and blood lactate values compared to healthy group. Serum glucose, Na, and Cl levels were also significantly lower, whereas serum K levels were significantly higher compared to healthy group. There was a positive correlation between pH and PaO₂, HCO₃, and BE concentrations, but a negative correlation between pH and PaCO₂ and lactate concentrations. The lung-specific epithelial and endothelial biomarkers in healthy and diarrheic neonatal calves with ARD included in the present study revealed that, serum ADMA and SP-D levels were significantly lower, while ET-1 concentrations increased significantly in diarrheic calves with RDS compared to control group measurements. The relationship between ADMA, ET-1 and SP-D concentrations, showed a very strong negative correlation between ADMA and SP-D concentrations and the concentration of ET-1. Whereas, a strong positive correlation between ADMA and SP-D concentrations.