Pneumothorax in Dogs and Cats: Emergency Signs and Treatment
In this article
By Dr Duncan Houston
If your dog or cat suddenly struggles to breathe, especially after an accident or bite, seek emergency care now. Pneumothorax is one possible cause: air has entered the space around the lungs.
The air is outside the lung rather than where it belongs inside the airways. As it accumulates, the lungs cannot expand normally, and severe cases can rapidly affect circulation as well.
Quick Answer
Pneumothorax is air in the pleural space around the lungs and can cause rapid, shallow or laboured breathing. It may follow trauma, arise from a leaking lung lesion or occur as a procedural complication. Treatment can require urgent removal of air, oxygen, a chest tube or surgery. There is no safe home method for judging or draining it.
How does air get into the chest?
A puncture wound can allow outside air through the chest wall. Blunt trauma can damage lung tissue without an obvious external wound. Air can also leak from an abnormal lung area, including a bleb or bulla, without a recent accident.
The Merck explanation of pleural air and fluid describes why the resulting loss of normal lung expansion causes breathing difficulty. “Spontaneous” means the event was not caused by obvious trauma or a procedure; it does not prove the lungs were healthy.
What is tension pneumothorax?
In tension pneumothorax, air continues to enter but cannot escape adequately. Rising pressure compresses lungs and interferes with blood returning to the heart. This is a rapidly life-threatening emergency that requires immediate veterinary decompression.
An unstable patient may need treatment before radiographs. Waiting for a perfect diagnostic image can be unsafe when clinical findings indicate a critical pleural-space problem.
How urgent are the signs?
| Finding | Action |
|---|---|
| New rapid breathing after trauma, even without a visible wound | Seek emergency assessment. |
| Open-mouth breathing in a cat, extended neck or obvious abdominal effort | Travel to an emergency clinic immediately. |
| Collapse, blue-grey gums or rapidly worsening weakness | Call ahead while transporting; critical stabilisation may be needed. |
A small pneumothorax may initially cause subtle signs, but owners cannot reliably determine its size or whether leakage is continuing.
What else can look similar?
Fluid or blood around the lungs, pulmonary bruising, diaphragmatic hernia, heart failure, pneumonia and asthma can cause similar breathing patterns. Several injuries may occur together after trauma. A chest wound that looks small on the surface can conceal significant internal damage.
How do vets diagnose and treat it?
Examination, bedside ultrasound and radiographs may identify pleural air. The immediate priorities are oxygenation, safe handling and relief of pressure. Thoracocentesis removes air using a veterinary needle or catheter technique.
If air keeps returning, a chest tube allows ongoing drainage and measurement of leakage. Merck’s emergency triage guidance describes this escalation when repeated drainage is needed.
CT and surgical assessment may be appropriate after stabilisation, particularly for persistent or spontaneous leaks. Surgery may remove an affected lung portion or repair injury. The decision depends on cause, continued leakage and the rest of the patient’s condition.
When is this an emergency?
Any suspected pneumothorax with breathing changes needs emergency care. Keep the animal in the position it finds easiest, minimise handling and avoid tight restraint around the chest. Do not remove an embedded object, probe a wound or attempt chest drainage. Ask the emergency clinic for transport instructions if there is an open chest injury.
Recovery after treatment
- Follow the prescribed rest period and prevent running, jumping and rough play.
- Monitor breathing at rest several times daily as directed.
- Give medicines exactly as prescribed and check any incision.
- Keep all tube or dressing instructions clear if specialised home care is required.
- Attend planned rechecks before returning to normal activity.
- Return immediately for renewed breathing effort or collapse.
Do not assume improved energy means the leak has fully healed. The veterinary team may use examination and imaging to decide when restrictions can be relaxed.
Common mistakes
- Waiting because there is no visible wound.
- Forcing a distressed animal to lie flat.
- Wrapping the chest tightly without veterinary direction.
- Resuming exercise before clearance.
Can it be prevented?
Secure fencing, road safety and preventing animal fights reduce traumatic risk. Spontaneous pneumothorax cannot always be predicted. After a previous episode, understanding the identified cause and recurrence plan is more useful than a general supplement or breathing exercise.
Frequently asked questions
Can a small pneumothorax resolve without surgery?
Some can under veterinary monitoring, but that decision requires assessment of the leak and the patient.
Does every pet need a chest tube?
No. The amount and persistence of air determine the drainage approach.
Can it come back?
Yes, particularly if the source of leakage remains. Ask about the cause-specific recurrence risk.
Rapid stabilisation and treatment of the leak give your pet the best opportunity for a comfortable recovery.
For help understanding your animal’s care and preparing questions for your veterinarian, visit ASK A VET™. Seek in-person emergency care immediately for urgent signs.
