Tension pneumothorax in the dog: radiographs or thoracocentesis
4-year-old German Shepherd hit by a car 30 minutes ago. It has rapidly worsening dyspnoea, cyanotic mucous membranes, a barrel-shaped chest, absent dorsal breath sounds bilaterally and hypotension.
What do you do first?
chevron_right Show answer and explanation
A. Immediate thoracocentesis, without waiting for radiographs
Correct. Clinical signs of tension pneumothorax are a life-threatening emergency: thoracocentesis is both diagnostic and therapeutic. If air reaccumulates rapidly, place a thoracostomy tube.
B. Three-view thoracic radiographs to confirm the diagnosis
This delays treatment, and handling the patient in recumbency may trigger an arrest. Radiographs are taken once the patient is stable.
C. Intravenous furosemide for possible pulmonary oedema or contusion
The findings (hyperresonance, absent dorsal breath sounds) indicate pleural air, not oedema; the diuretic would also worsen the hypotension.
D. Intubate and ventilate with positive pressure before draining
Positive-pressure ventilation without drainage increases intrapleural pressure and worsens the tension pneumothorax and circulatory collapse.
lightbulb Key takeaway
Radiographically, pneumothorax separates the heart from the sternum on the lateral view and retracts the lobes, leaving a space without vascular markings between lung and wall. In tension pneumothorax there is also flattening and caudal displacement of the diaphragm and increased thoracic volume. Heart elevation on the lateral can be an artefact: confirm on the DV/VD or with ultrasound (absent lung sliding).
Test yourself with 10 random questions
Diagnostic imaging · 200 questions, a different test every time
Related questions
Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.