Bronchopulmonary Disease in the Cat: Historical, Physical, Radiographic, Clinicopathologic, and Pulmonary Functional Evaluation of 24 Affected and 15 Healthy Cats

The results of clinical and pulmonary functional evaluation of 24 cats with bronchopulmonary disease and 15 healthy cats are presented. Affected cats had historical evidence of excessive reflexes (coughing, sneezing); physical evidence of airway secretions (crackles), obstruction (wheezing), and increased tracheal sensitivity; radiographic evidence of bronchial and interstitial lung disease; and cytological evidence of airway inflammation or mucous secretions. Bacterial isolates from healthy and affected cats were predominantly Gram-negative rods, indicating that bronchi of cats are not always sterile and that normal flora should be considered in interpreting cultures from cats with suspected bronchopulmonary disease. Cats were grouped according to relative disease severity based on scored historical, physical, and radiographic abnormalities. The mean (± standard deviation) baseline lung resistance measurement in healthy cats was 28.9 cm H₂O/L/s (±6.2 cm H₂O/L/s), whereas in mildly, moderately, and severely affected cats it was 38.3 cm H₂O/L/s (±21.5 cm H₂O/L/s), 44.8 cmH₂O/L/s (±7.7 cm H₂O/L/s), and 105.2 cm H₂O/L/s (±66.9 cm H₂O/L/s), respectively. In healthy cats, dynamic lung compliance was 19.8 (±7.4), whereas in mildly, moderately, and severely affected cats it was 14.7 mL/cm H₂O (±3.8 mL/cm H₂O), 17.7 mL/cm H₂O (±6.9 mL/cm H₂O), and 13.0 mL/cm H₂O (±7.9 mL/cm H₂O), respectively. Thus, airway obstruction was present in many of the affected cats. Based on acute response to the bron-chodilator, terbutaline, airway obstruction was partially reversible in many affected cats, although the degree of reversibility varied. Furthermore, based on bronchoprovocation testing, 6 (of 7) affected cats evaluated also had increased airway responsiveness to aerosolized methacholine.