Bullous emphysema and recurrent pneumothorax in the dog.

Six cases of recurrent pneumothorax requiring surgical intervention in the dog were reviewed. Radiography was not useful in identifying the source of air leakage. A median sternotomy approach was useful for identifying and removing involved lung tissue. All 6 dogs had microscopic evidence of bullous emphysema. Bronchiolitis, thickened pleura, and bronchiolar smooth muscle hypertrophy also were noticed. Underlying mild obstructive lung disease alone or in combination with a defect in pulmonary collagen probably predisposed these dogs to bullous emphysema and recurrent pneumothorax. Of the 6 dogs, 3 survived for at least 2 years after surgery.