On-farm diagnosis of bronchopneumonia in calves
The study determined the informational value of various clinical tools for the diagnosis of bronchopneumonia in calves in a farm environment. We examined 122 Red-Motley calves at the age of 14-42 days in two farms of the Voronezh region. The conventional animal study regimen was supplemented with chest ultrasound (US) and clinical scoring according to the Wisconsin respiratory scoring chart® (WRSC). The informational value of predictors for the diagnosis of bronchopneumonia was determined using the ROC curve; the relationship between the indicators was determined using the Kendall rank correlation coefficient. According to the results of ultrasound examination, bronchopneumonia was diagnosed in 35.6% of calves. Thermometry sensitivity was 25.0%; specificity was 93.3%; critical value was more than 39.5 C. The sensitivity for determining the respiration rate was 34.4%; the specificity was 91.1%; the critical value was more than 41 brpm. We found a weak correlation between the degree of lung damage and the respiratory rate of animals (r = +0.24, p was less than 0.01). The WRSC value depended on the method of provoking the cough. When the scoring was performed by palpation of the lower third of the trachea (WRSC1) the sensitivity was 65.6%, the specificity was 75.6%, and the critical value was more than 3 points. When coughing was provoked by simultaneous palpation of the lower third of the trachea and 30-second expiratory apnea (WRSC2), the values of these indicators were 100.0%, 75.6%, and more than 3 points, respectively. A moderate positive correlation was found between the WRSC2 score of calves and the degree of lung damage (r = +0.62, p was less than 0.01). With thoracic auscultation, wheezing was the most valuable for diagnosing bronchopneumonia. We found a significant correlation between wheezing during chest auscultation and the degree of lung damage (r = +0.46, p was less than 0.001). The sensitivity of the predictor for the diagnosis of bronchopneumonia was 71.9%; the specificity was 77.8%