Recurrent spontaneous pneumothorax in four surgically treated Japanese Spitz dogs

Four Japanese Spitz dogs between 5 and 11 months old were presented for acute dyspnoea. Thoracic radiographs and CT identified bilateral pneumothorax and pulmonary cavitary lesions. The median lesion size was 30 mm (range 7‒50 mm). After initial stabilisation, one dog underwent median sternotomy, while three dogs underwent intercostal thoracotomy. Surgical exploration found grossly haemorrhagic pulmonary bullous lesions in all cases. Histopathology revealed blood-filled cavities with interstitial fibrosis and pneumocyte hyperplasia. Dyspnoea recurred in all dogs postoperatively, with recurrence of lesions confirmed either radiographically or via CT in three of four cases. The median time from surgery to recurrence of pneumothorax was 9 days (range 5‒15 days). The mortality rate was 100%, and the median postoperative survival time was 22 days (range 5‒558 days). This report aims to raise awareness of this group of dogs presenting with spontaneous pneumothorax at a young age and with high recurrence rates despite surgery, contrary to the literature.