Pneumothorax in cats means air has collected in the pleural cavity, the thin space between the lungs and the chest wall. When enough air builds up, the lung cannot fully expand, and the cat has trouble breathing in. Merck Veterinary Manual’s cat-owner guidance calls this condition an emergency. If your cat is breathing fast, working hard to breathe, or has pale, gray, or bluish gums, take it to a veterinarian or 24-hour emergency hospital now, and call ahead so the team can prepare.
What to do right now
- Call the nearest 24-hour emergency veterinary hospital, or your regular vet if they are open, and say your cat has difficulty breathing.
- Keep the cat calm and confined. A carrier or a towel-lined box keeps movement to a minimum.
- Do not try to drain air, restrain the chest, or give leftover medications. Home treatment can delay the care this condition needs.
- Bring any history you have: recent falls, car accidents, bite wounds, coughing, known asthma or lung disease, and any medications the cat takes.
What pneumothorax is and why it makes breathing hard
The lungs normally sit in a sealed space that holds only a small amount of fluid and no air. Air that enters this space pushes against the lungs, and the lungs cannot inflate as they should. Merck describes large air volumes in the pleural space as capable of collapsing the lung. In some cases the mediastinum, the membrane-like partition between the two sides of the chest, is weak or incomplete, which allows air to affect both lungs.
Causes of pneumothorax in cats
Veterinary references divide pneumothorax into traumatic and spontaneous forms. The cause shapes both the treatment and the outlook, so identifying it is part of the workup.
Traumatic pneumothorax
Air can enter through a penetrating wound in the chest wall. Merck’s trauma guidance treats this as a separate category from spontaneous disease because the injury itself is the main problem to address, and it may need surgical repair if air keeps leaking.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
- 【Cat Inhaler Mask Designed for Cats and Small Dogs】Designed for the unique facial structure and size of pet cats and small dogs, it provides a more comfortable and less stressful experience for pets. A well-fitting mask can also reduce discomfort or irritation. So as to inhale better
- 【Pet Silicone Mask - Safe and Reliable】Inhaler mask for cats，made of silicone, the safe and comfortable material meets pet health standards, ensuring that it will not negatively affect the health of pets in an emergency.
- 【Equipped with oxygen tube and longer length】This pet oxygen mask kit includes a 2-meter oxygen tube, which is longer than the common 1.5-meter oxygen tube on the market for connecting to the equipment. The extended oxygen tube allows pets to be farther away from the equipment, further reducing noise and making it easier for pets to accept, Conveniently provide oxygen for dogs cats
- 【Versatile pet oxygen mask kit, simple and easy to use】The kit includes a pet-specific silicone mask, oxygen tube and connector, suitable for a variety of pet environments, such as home, cat and dog first aid, pet rescue, and easy to carry.
- We specialize in designing and producing pet cats and dog oxygen masks, inhaler masks and related products, we take full responsibility for any quality problems that may arise. If there is any problem with the goods you received, please contact us and we will deal with it for you immediately.
Spontaneous pneumothorax linked to lung disease
Spontaneous pneumothorax occurs without an obvious injury. Merck names pulmonary emphysema and ruptured bullae, which are air-filled pockets in the lung wall, as sources of air leakage. In cats, spontaneous cases are usually secondary, meaning they arise from an underlying lung problem rather than standing alone. In a published retrospective series of 16 cats treated at a referral hospital between 2000 and 2012 (Liu and Silverstein, Journal of Veterinary Emergency and Critical Care, 2014), 14 cats had multilobar lung disease from infectious, inflammatory, or neoplastic causes. Asthma was the most common identified cause, present in four of the 16 cats (25%).
This was a small hospital series, so it shows what the cats in that group had rather than how common each cause is in cats generally.
Congenital abnormalities
Rarely, a focal congenital abnormality of the lung is the cause. In the same 16-cat series, one cat with congenital accessory lung-lobe emphysema was treated with a lobectomy, which removed the affected lobe and was curative in that cat.
Rank #2
- Flow Rate: 1 liter per min - 40 liters per minute
- FiO2 - 24% - 90% (it does not go higher)
- This is Standard size mask that fits most of the adults.
- Model OP-1125-8 is for those who might have a large face or have a mustache. It is about 25% larger than standard mask - OM-1125-8
Signs to watch for
Owners often describe a cat that is breathing rapidly, breathing shallowly, seems weak, or appears to strain on each inhalation. Merck’s cat-owner reference specifically links difficulty inhaling and rapid, shallow breathing to significant air in the chest.
Early signs
- Faster breathing or an increased breathing effort at rest
- Restlessness, reluctance to lie down, or a hunched posture
- Weakness or reduced activity
Late signs
Emergency guidance from Merck’s triage material describes open-mouth breathing and gray, dark pink, or blue mucous membranes as late signs. These indicate substantial loss of lung function and a risk of respiratory arrest. Do not wait for late signs before seeking help, because the early signs already justify urgent care.
How veterinarians confirm the diagnosis
The first priority is stabilizing the cat, not completing a full diagnostic set. Examination may show asynchronous or paradoxical movement of the chest and abdomen and muffled lung sounds. These findings suggest a problem in the pleural space, but fluid or other material can cause the same pattern, so they do not confirm air on their own. Stressful handling or positioning can worsen a fragile patient, so the team will choose tests carefully.
Rank #3
- 【Veterinary-Grade Respiratory Support】Soft-seal dome minimizes oxygen loss and provides stable delivery, ideal for respiratory distress, chronic airway disease and emergency stabilization in animals of various sizes.
- 【Engineered Oxygen Flow Efficiency】Specialized vent design enhances oxygen concentration while directing exhaled CO₂ outward, maintaining cleaner airflow and supporting consistent therapy sessions.
- 【Comfortable Fit for Reduced Stress】Flexible silicone interface adapts to different face shapes, reducing anxiety and improving tolerance during oxygen therapy for dogs, cats and other small pets.
- 【Complete Multi-Size Mask Kit】Includes five mask sizes and a 7-ft oxygen tube compatible with most concentrators and portable tanks, supporting flexible use across different treatment rooms and field units.
- 【Reliable for High-Volume Care Settings】Well-suited for clinics, EMS teams, shelters, wildlife groups and rescue units relying on durable, easy-clean oxygen masks for frequent and varied patient needs.
- Thoracic radiographs (X-rays) are useful when the cat is stable enough to be positioned for them.
- Point-of-care ultrasound can be used by a skilled operator. Merck describes absent pleural "glide" (the normal sliding of lung against the chest wall on ultrasound) as a possible sign of pneumothorax.
- Imaging should not delay treatment in a cat that is in respiratory distress.
Treatment options and how they are chosen
Treatment is provided by a veterinary team and depends on how severe the breathing problem is and what is causing it. Emergency care usually begins with oxygen and removal of the air.
| Option | What it involves | When it is typically considered |
|---|---|---|
| Oxygen support | Supplemental oxygen to improve breathing while the air is managed | Any cat with respiratory distress |
| Thoracocentesis | A needle or catheter is placed in the chest to withdraw air from the pleural space | First-line removal of air in an emergency |
| Thoracostomy tube | A tube left in the chest for continuous drainage | When negative pressure cannot be achieved or air keeps returning after aspiration |
| Surgical exploration | Opening the chest to find and repair the leak or remove a diseased lobe | When air keeps leaking despite drainage, or a focal lesion is identified |
Medical management
The 16-cat series concluded that supportive medical management is the most appropriate approach for feline secondary spontaneous pneumothorax. Surgery is reserved for rare cases with focal congenital abnormalities. Surgery is not standard for every cat with pneumothorax.
Surgery and ongoing leakage
Merck’s trauma guidance identifies ongoing air leakage after 72 hours of pleural drainage as an indication for surgical exploration. This is professional guidance for the veterinary team, not a rule owners can apply at home.
Rank #4
- 【Stable Fit for Reliable Anesthetic Delivery】Six graduated mask sizes help achieve a consistent seal for pets from small mammals to medium-sized dogs, reducing gas loss and supporting efficient induction.
- 【Ready for Standard Veterinary Systems】Universal connector attaches to most anesthesia machines without adapters, allowing rapid transitions between procedures such as exams, imaging, dental cleanings and soft-tissue work.
- 【Designed for Animal Comfort】Light, clear dome and flexible silicone perimeter limit pressure and reduce patient resistance, promoting smoother inductions even with anxious animals.
- 【Durable Build for Repeated Use】Tough medical-grade construction withstands routine handling, while the detachable design simplifies deep cleaning, disinfection and long-term maintenance.
- 【Supports Busy Clinical Environments】A practical solution for surgery centers, teaching facilities, multi-room clinics and high-volume hospitals managing diverse species every day.
Factors veterinarians weigh
- The underlying cause: trauma or spontaneous lung disease
- Whether the disease appears diffuse across the lungs or focal in one area
- Whether breathing improves after the first drainage
- Whether air keeps leaking or reaccumulates
- Whether the cat is stable enough for imaging or anesthesia
The available feline evidence supports decisions based on the specific cause. It is too limited to compare treatment success across all cats.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Outlook and what the published numbers mean
Prognosis depends on the cause and on the cat’s condition when treatment starts. Feline outcome data come from small retrospective studies and case literature. They are useful for understanding patterns but cannot predict how an individual cat will do.
| Source | Group studied | Result reported | Limits |
|---|---|---|---|
| Liu and Silverstein, 2014 | 16 cats with secondary spontaneous pneumothorax, 2000–2012 | Asthma was the most common cause (25%); 10 of 12 treated cats survived to discharge with medical management, including all four asthma cases; recurrence documented in four cats | Single referral-hospital series; not a population rate or guarantee of outcome |
| Literature review, 2017 ("Spontaneous pneumothorax in cats: two case reports and literature review") | 64 previously reported cases of secondary spontaneous pneumothorax, drawn from nine articles | 39 of 64 cats (60%) were discharged | Selected published cases with differing diseases and treatments; not a prediction for a given cat |
The authors of the 2014 series described the short-term outlook for asthma-associated cases as good. They also stressed that clinical assessment, imaging, and invasive diagnostic tests are needed to separate asthma-associated cases from other causes.
Recommended Free Tools
Best Value
- MPORTANT – CHECK SIZE BEFORE ORDERING: This listing includes 1 pet oxygen mask for cats and dogs. Fit is determined primarily by the pet's facial and snout dimensions rather than breed or body weight. Please carefully compare your pet's face and snout measurements with the size chart shown in the product images before ordering.
- DESIGNED FOR CATS & DOGS: Suitable for a variety of appropriately sized cats and dogs when the mask can properly cover the nose and mouth area. Because facial structure varies significantly between breeds and individual pets, breed and weight recommendations are for reference only.
- STANDARD CONNECTION: Designed to connect with compatible pet and veterinary oxygen concentrator systems through a standard connector. Please verify the connector size and compatibility of your equipment before purchase.
- CLEAR MASK FOR EASY OBSERVATION: Transparent mask construction keeps the pet's nose and mouth area visible during use, helping with positioning and observation. Durable, easy-to-clean materials make it suitable for routine veterinary and home pet care.
- FOR PET / VETERINARY USE ONLY: Intended solely as an accessory for pet and veterinary oxygen equipment. Not for human use. This product does not generate oxygen independently and must be connected to compatible equipment. Use under appropriate veterinary guidance when required.
What owners can and cannot do at home
No home treatment or monitoring device treats pneumothorax. Owners can help most by recognizing breathing changes early, acting on them quickly, and giving the veterinary team a clear history. Ask your vet about the cause, recurrence risk, and what signs should prompt an immediate return visit after discharge. The cat-owner guidance from Merck is available through the Merck Veterinary Manual, in the chapter “Disorders of the Chest Cavity of Cats” (reviewed August 2018, last updated September 2024).
Merck’s cat-owner guidance states: "This condition should be considered an emergency that requires immediate veterinary attention."
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
