Pneumothorax in Cats


Overview of Pneumothorax in Cats

Pneumothorax is the abnormal presence of air within the chest cavity, which restricts the lungs from inflating normally during inhalation. Air is normally confined to spaces within the lungs.

Pneumothorax can be sub-divided into the following categories:

  • Open pneumothorax – occurs when a penetrating chest wound allows outside air to enter the pleural space
  • Closed pneumothorax – occurs when the source for the introduction of air into the intrapleural space has closed so that no more air can enter.
  • Tension pneumothorax – occurs when air fills the chest cavity with each breath and is not allowed to exit (a one-way valve effect)
  • Spontaneous pneumothorax – a closed pneumothorax that occurs unexpectedly; no trauma is involved.
  • Traumatic pneumothorax – pneumothorax resulting from traumatic injury to the chest
  • General Causes of Pneumothorax 

    Pneumothorax can be the result of any of the following:

  • Perforation of the chest wall secondary to bite wounds, automobile accidents, gunshot wounds, stab wounds, or other penetrating injuries
  • Rupture of a pulmonary (lung) cyst, bullae (cyst-like structure within the lungs) or bleb (tiny cyst-like structure on the outer surface of the lungs) that occurs spontaneously. This type of pneumothorax is more common in older animals.
  • Rupture of a bronchus (main airway)
  • Rupture of the trachea (the windpipe)
  • Rupture of the esophagus
  • Rupture of the lung tissue
  • Rupture of the mediastinum, which is a confined space within the chest cavity but independent of the lungs

    Cats with pneumothorax exhibit difficulty breathing and, in severe cases that are left untreated, pneumothorax can be fatal.

  • What to Watch For

  • Increase in the respiratory rate (more than 45 breaths per minute)
  • Labored breathing
  • Cyanotic (blue) gums or tongue
  • Intolerance to exercise
  • Diagnosis of Pneumothorax in Cats

    Depending on how much difficulty breathing your cat is experiencing, your veterinarian may want to place him in an oxygen cage immediately before obtaining a history from you regarding his condition. Your veterinarian will perform a thorough physical examination with careful auscultation (listening with a stethoscope) of your cat’s chest to determine the cause of trouble breathing. Additionally, your veterinarian will likely recommend the following tests:

  • Chest radiographs (X-rays) to look for the presence of air in the chest cavity
  • Thoracocentesis, which is removal of air from the chest cavity with a needle and syringe.
  • Arterial blood gas, a test to evaluate the cat’s ability to oxygenate
  • Pulse oximetry, a non-invasive test to determine the cat’s ability to oxygenate
  • Complete blood count (CBC) to assess the cat’s general health
  • Biochemistry profile to evaluate the internal organs such as the liver and kidneys
  • Treatment of Pneumothorax in Cats

    Treatment of a pneumothorax may need to be done as an emergency procedure and may include any of the following:

  • Supplemental oxygen administration for cats that are having difficulty breathing
  • Thoracocentesis to remove air from the chest cavity and to improve the cat’s ability to breathe
  • Chest tube placement to allow larger amounts of air to be removed from the chest cavity more quickly or continuously
  • Thoracic surgery to repair large air leaks within the chest or to repair damage to the chest wall that may be present with traumatic injuries
  • Home Care and Prevention

    Cats that show signs of difficulty breathing should be taken to your veterinarian immediately. Restrict exercise initially following discharge from the hospital.

    Keeping cats indoors can reduce the risk of pneumothorax caused by traumatic injuries due to automobile accidents or attacks by other animals.

    There is no way to prevent a spontaneous pneumothorax from occurring.

    In-depth Information on Pneumothorax in Cats

    The chest cavity does not normally contain air, except for air within the lungs. Any air in the chest cavity is abnormal. A pneumothorax develops when air is allowed into the chest cavity through a breach in the chest wall due to injury (external leak), and/or air leaks into the chest cavity due to a leak in the lung tissue or airways (internal leak).

    The presence of air within the chest cavity exerts pressure on the lungs so they cannot expand or inflate when the pet tries to take a breath. Large volumes of air cause the lungs to collapse completely. If the lungs do not inflate normally or are collapsed, the pet cannot obtain enough oxygen and develops signs of difficulty breathing such as rapid, shallow breaths, and cyanotic (blue) gums and tongue. The volume of air and the rate at which it accumulates within the chest varies with the degree of traumatic injury or underlying problem.

    Pets with pneumothorax require hospitalization for an average of two to five days.


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