Chronic Bronchopneumonia in Cattle

Abstract

Twenty-five calves had the following clinical signs of chronic bronchopneumonia: depression, gaunt appearance, subnormal appetite, bilateral mucopurulent nasal discharge, increased respiratory and heart rate, inspiratory or expiratory dyspnoea, infrequent cough, and an average rectal temperature of 103.5 deg F. On auscultation normal vesicular or harsh vesicular sounds were heard most commonly in the dorsal tripartition, moist or dry rales in the middle tripartition, and dry rales in the ventral tripartition. Changes associated with chronic bronchopneumonia decreased arterial blood pH, PO2, HCO3, total CO2, and base excess. These values (except oxygen tension) were also low in venous blood. Contrast bronchograms revealed extensive consolidation and atelectasis of the apical lobes and cardiac and diaphragmatic lobes ventral to the trachea. Angiograms revealed decreased blood supply to areas of the lung affected with chronic bronchopneumonia. Gross pathological changes were atelectasis and consolidation of the anterior ventral aspect of the lungs  and emphysema dorsally. Histological changes consisted of atelectasis, emphysema, fibrous thickening of alveolar septa, abscess formation, peribronchial lymphocytic hyperplasia, and obstructive bronchiolitis.