OBJECTIVE To describe the clinical course, diagnostic findings, medical and surgical treatments, and outcome in a dog with spontaneous pneumothorax secondary to necrotizing pneumonia thought to be a delayed complication of heatstroke. CASE SUMMARY A 1.5-year-old Labrador Retriever developed spontaneous pneumothorax 12 days after an episode of exertional heat stroke. Computed tomography was performed and showed bilateral pneumothorax and multifocal pulmonary consolidation, especially at the lung periphery. A median sternotomy was performed, and multifocal, well-demarcated areas of consolidated pulmonary tissue with purple discoloration were identified and resected from the right middle, right caudal, and accessory lung lobes. Histologic examination of the resected pulmonary tissue indicated necrotizing pneumonia, and bacteriologic culture of the tissue resulted in growth of Pseudomonas aeruginosa. Examination of tissue from a pectoral muscle biopsy performed at this time showed necrotizing myopathy. The dog was discharged 7 days after surgery and made a full recovery. NEW OR UNIQUE INFORMATION PROVIDED This case report describes pneumothorax and multifocal necrotizing pneumonia as a delayed complication of heatstroke, and provides the first description of the computed tomography appearance of histologically confirmed necrotizing pneumonia in a dog. Multifocal necrotizing pneumonia with or without pneumothorax should be considered in dogs that develop respiratory distress following severe systemic illness.
Pneumothorax in a dog caused by necrotizing pneumonia secondary to heatstroke.