A 6-year-old male castrated German shorthaired pointer presented to a local veterinary practice for a 2-month history of lethargy after exercise and an acute onset of dyspnea. There was no known history of trauma. Radiographs showed pneumothorax with a probable bulla in the right lung and the patient was referred to the Cornell University Hospital for Animals. A CT scan revealed multiple pulmonary bullae and the patient underwent of right lateral thoracotomy. The right caudal and accessory lung lobes were completely resected. Histopathology confirmed focal pulmonary bullae and blebs with multifocal areas of hemorrhage, fibrosis and emphysema. Primary spontaneous pneumothorax associated with ruptured pulmonary bullae or blebs is an uncommon disease in dogs and the pathogenesis is not well understood. Retrospective studies have shown that surgical resection of affected lung tissue is the most effective treatment option and that the prognosis is good. Unfortunately the patient had recurrence of multifocal bullae one month following surgery and euthanasia was elected. A post-mortem exam confirmed the diagnosis of pulmonary bullae/blebs with mild secondary viral pneumonia.