Canine Pneumothorax Study Guide

Overview and Clinical Importance

Pneumothorax is defined as the abnormal accumulation of free air within the pleural space. This condition disrupts the normal negative intrapleural pressure (approximately -5 cmH2O), causing partial or complete lung collapse and significant respiratory compromise. Pneumothorax is a common emergency presentation in dogs and represents a high-yield topic on the NAVLE, requiring understanding of classification, diagnosis, emergency management, and definitive treatment.

The condition can be life-threatening if not promptly recognized and treated. Traumatic pneumothorax is the most common form, occurring in approximately 50% of significant thoracic trauma cases in dogs. Spontaneous pneumothorax, while less common, requires thorough understanding due to its high recurrence rate without surgical intervention.

Classification of Pneumothorax

Etiological Classification

1. Traumatic Pneumothorax

Traumatic pneumothorax is the most common cause of pneumothorax in dogs. It results from injury to the chest wall, airways, or lung parenchyma. Common causes include motor vehicle accidents, bite wounds, blunt force trauma, rib fractures, and penetrating injuries.