Pneumothorax in Dogs — Management Guide

Practical, evidence-based guide to recognizing, diagnosing and managing pneumothorax in dogs — from emergency decompression to chest tubes, surgery and long‑term care.

Quick Overview

• What it is: Pneumothorax is the presence of air in the pleural space (between lung and chest wall) that interferes with normal lung expansion. In dogs it may be traumatic, iatrogenic, or spontaneous (often due to ruptured pulmonary bullae/blebs or underlying lung disease).
• Who’s at risk: Any dog following chest trauma (hit by car, bite, penetrating wound), dogs with pulmonary bullae (larger or deep‑chested breeds), or those with pulmonary infections or neoplasia. Deep‑chested breeds (e.g., Greyhounds, Whippets) and older dogs with degenerative lung disease are over‑represented in spontaneous cases.
• Prognosis: Highly variable. Simple pneumothorax that is rapidly decompressed and treated has an excellent prognosis. Tension pneumothorax is life‑threatening and requires immediate intervention. Dogs with recurrent spontaneous pneumothorax from bullous disease often need surgery; many do well after definitive treatment.

Pathophysiology — explained simply

The lungs normally fill the thoracic cavity and are held against the chest wall by negative pressure in the pleural space. If air enters the pleural space (from outside the chest or leaking from the lung), that negative pressure is lost. The lung collapses to a degree determined by the volume of air and the dog’s respiratory reserve:

• Small pneumothorax: only part of the lung collapses; the dog may have mild respiratory signs.
• Large pneumothorax: substantial collapse of lung tissue results in marked respiratory distress and hypoxia.
• Tension pneumothorax: a flap or valve effect allows air into the chest but not out, rapidly increasing intrathoracic pressure, shifting mediastinal structures, compressing the opposite lung and large veins — this causes cardiovascular collapse and is an emergency.

• Deep‑chested, athletic breeds (Greyhounds, Whippets, Dobermans) are more prone to spontaneous pneumothorax from ruptured apical bullae.
• Middle‑aged to older dogs are more often affected by spontaneous bullous disease.
• Traumatic pneumothorax can occur in any dog following blunt or penetrating chest trauma; prevalence depends on injury rates in a population.

Symptoms and clinical grading

Common signs

• Rapid, shallow breathing (tachypnea)
• Open‑mouthed breathing (in severe cases)
• Increased effort to breathe, particularly on inspiration
• Reduced or absent lung sounds on auscultation, often dorsally
• Cyanosis, collapse, weakness (severe cases)
• Signs of trauma (rib fractures, wound) or concurrent illness

• Severe respiratory distress, marked tachypnea
• Very weak peripheral pulses, hypotension
• Visible neck vein distension (may be hard to appreciate in dogs)
• Rapid deterioration — immediate decompression required

Initial assessment (on presentation)

• Rapid triage: assess airway, breathing, circulation. Administer oxygen immediately if hypoxic.
• Brief focused physical exam: auscultation (diminished/absent lung sounds), palpation for subcutaneous emphysema, detection of chest wall wounds.
• Thoracic focused ultrasound (point‑of‑care ultrasound/FAST): can detect absent lung sliding or free pleural air quickly at bedside.

• Thoracic radiographs (right and left lateral ± DV/VD): classic signs include loss of pulmonary detail, retraction of lung lobes from the chest wall, and a sharp pleural line. Radiographs are often done after initial stabilization.
• Thoracic ultrasound: fast and sensitive for detecting pleural effusion and pneumothorax at the bedside; absence of lung sliding and presence of a “lung point” are useful signs.
• Computed tomography (CT): most sensitive for detecting pulmonary bullae, blebs, and underlying parenchymal disease when surgical planning is needed.
• Bloodwork: evaluation for shock, oxygenation (pulse oximetry, arterial blood gas if available), and concurrent conditions.

• Persistent air leak despite chest tube
• Recurrent spontaneous pneumothorax
• Complex chest trauma or suspected diaphragmatic rupture
• Need for thoracoscopic (VATS) or open thoracotomy surgical repair

Immediate/emergency management

1) Oxygen therapy

• Provide supplemental oxygen immediately (flow‑by, oxygen cage, nasal cannula) to improve oxygenation and decrease respiratory effort.

• Indication: any suspected large pneumothorax or tension pneumothorax.
• Technique: place a large‑bore over‑the‑needle catheter (e.g., 14–18 gauge for medium/large dogs) or a butterfly catheter into the pleural space. Insert at the level of the 7th–9th intercostal space in the dorsal third of the hemithorax (just behind the scapula line) or at the point of maximum dullness; aspirate air with syringe and catheter while allowing the chest to decompress.
• Monitor: reassess respiratory rate, effort, and pulse ox immediately. Thoracocentesis is lifesaving but may need repeated attempts.
• Risks: organ puncture, bleeding, introduction of infection — perform with care.

3) Chest tube (thoracostomy) placement

• Indication: ongoing or recurrent air accumulation, persistent air leak, or need for continuous drainage/suction.
• Tube size: choose tube diameter by dog size — e.g., 8–12 Fr for small dogs, 14–20 Fr for medium/large dogs; some clinicians use standard French sizes. Sterile technique and secure suturing are essential.
• Placement: typically in the 7th–9th intercostal space; the tube is advanced cranially and dorsally to drain air. Attach to an underwater seal or suction device (closed drainage). A Heimlich valve can be used for ambulatory management in select stable cases.
• Suction: intermittent or low continuous suction may be used; many clinicians avoid high negative pressures. Monitor drainage volumes, air leak (bubbling), and respiratory status.
• Success rates: many dogs with simple pneumothorax resolve with chest tube drainage alone; reported success is variable across studies but commonly cited as majority of cases avoiding immediate surgery.

• Opioid analgesics (e.g., hydromorphone 0.05–0.1 mg/kg IV, fentanyl bolus 2–5 μg/kg IV or CRI, morphine 0.1–0.5 mg/kg IV/SC) are commonly used to control pain and reduce stress‑related respiratory compromise. (Doses should be tailored to patient size, status and local practice.)
• Sedation for drainage or tube placement may be required; benzodiazepines (e.g., midazolam) or low doses of opioids are commonly used.
• Antibiotics only if there is contamination (penetrating wound) or suspected infection.

When surgery is indicated

• Persistent, large, or recurrent air leak despite an appropriately placed chest tube
• Recurrent spontaneous pneumothorax (often due to pulmonary bullae)
• Identified pulmonary pathology on imaging (large bullae, focal disease amenable to resection)

• Video‑assisted thoracoscopic surgery (VATS): minimally invasive, allows visualization and resection (stapled bullectomy) and pleurodesis; less postoperative pain and shorter recovery compared with open thoracotomy.
• Thoracotomy and bullectomy/lung lobectomy: standard open procedure when VATS is not available or when a larger resection is required.
• Pleurodesis (chemical or mechanical): used when diffuse pleural disease or recurrent pneumothorax makes resection impractical; talc pleurodesis or surgical abrasion can create adhesions to prevent reaccumulation of air.

• Reported success of surgical treatment for spontaneous pneumothorax due to bullae is generally good: many series report low recurrence after definitive surgical resection and pleurodesis, with survival rates commonly >80–90% to discharge in elective surgical cases (varies by study and patient stability).
• VATS provides equivalent efficacy to open surgery in many reports with lower morbidity.

• Bullae and blebs are focal air‑filled spaces within the lung parenchyma that can rupture and cause spontaneous pneumothorax.
• Management: small, asymptomatic bullae found incidentally can be monitored. Symptomatic or ruptured bullae that cause pneumothorax are candidates for elective surgical resection (bullectomy) often performed thoracoscopically.
• Long‑term: dogs with multifocal bullous disease that cannot be completely resected may have a higher risk of recurrence and may require repeated interventions or pleurodesis.

• Activity restriction: limit vigorous activity for several weeks after resolution or surgery to reduce recurrence risk.
• Follow‑up imaging: chest radiographs are typically repeated after stabilization and prior to discharge; recheck radiographs at intervals (e.g., 2–4 weeks post‑treatment) or sooner if signs recur.
• Owner monitoring: owners should watch for increased respiratory rate at rest, coughing, lethargy, or collapse and report these promptly.
• For dogs with chest tubes at home (Heimlich valve), owners must be trained in care and monitoring and have close follow‑up with the veterinary team.

• Many dogs fully recover from a single pneumothorax episode after appropriate emergency care and drainage.
• Dogs with underlying lung neoplasia, severe traumatic lung injury, or diffuse bullous disease have a more guarded prognosis.
• After successful surgical treatment of bullous disease, most dogs regain good quality of life with return to normal activity after recovery.

• Restrict exercise: short leash walks only until cleared by your veterinarian.
• Keep stress low: avoid excitement that increases respiratory rate.
• Monitor respiratory rate: measure resting respiratory rate (count breaths per minute while the dog is asleep or resting); a persistently high rate (>30–40 breaths/min at rest in many dogs) warrants veterinary evaluation.
• Watch the incision or chest tube site: redness, swelling, drainage, or sudden changes in breathing need prompt attention.
• Plan for emergencies: trainees and owners of dogs with prior pneumothorax should know nearest emergency facility and keep contact numbers handy.

• Any sudden increase in respiratory rate or effort, open‑mouthed breathing, collapse or pale/cyanotic gums
• Swelling or new drainage at a chest wound or chest tube site
• Sudden lethargy, fainting, or weakness after recent chest trauma or surgery

• Thoracocentesis: over‑the‑needle catheter (e.g., 14–18G) placed in dorsal 1/3 of hemithorax, usually at the 7th–9th intercostal space; aspirate with syringe.
• Chest tubes: choose French size appropriate to dog’s size (8–20 Fr commonly used across sizes); secure with Chinese finger‑trap or suture and use closed drainage.
• Analgesics: commonly used opioids include hydromorphone 0.05–0.1 mg/kg IV, fentanyl 2–5 μg/kg IV or CRI, morphine 0.1–0.5 mg/kg IV/SC; adjust to patient and hospital protocols.
• Antibiotics: not routinely necessary unless contaminated wound or septic process is suspected.

• Pneumothorax ranges from mild to life‑threatening (tension). Rapid recognition and oxygenation are critical.
• Emergency thoracocentesis is frequently lifesaving; chest tubes provide continuous drainage for persistent leaks.
• Recurrent spontaneous pneumothorax often reflects bullous disease and typically requires surgical evaluation — VATS or thoracotomy with bullectomy and pleurodesis have good outcomes.
• Long‑term prognosis depends on underlying cause, but many dogs return to normal life after appropriate treatment.

Sources and further reading

• Merck Veterinary Manual — Pneumothorax in Small Animals. https://www.merckvetmanual.com/respiratory-system/respiratory-diseases-of-small-animals/pneumothorax-in-small-animals
• Fossum TW. Small Animal Surgery, 5th Ed. (section on thoracic surgery and chest tube management).
• Selected peer‑reviewed reports and surgical reviews in Veterinary Surgery and Journal of Veterinary Internal Medicine describing thoracostomy and surgical treatment of spontaneous pneumothorax.
• Specialty colleges (ACVIM/ACVECC) resources and continuing education articles on emergency thoracic management.

Frequently Asked Questions