Pneumothorax in Dogs
Related Symptoms or Diseases
There are many other problems involving the lungs that could produce symptoms similar to those observed with pneumothorax, such as:
Pleural effusion. An accumulation of fluid in the chest cavity restricts the lungs from inflating normally when the animal takes a breath. Types of fluid that may accumulate, include blood (hemothorax), chyle (chylothorax), pus (pyothorax), and clear fluid (hydrothorax). The presence of fluid in the chest is abnormal regardless of its origin.
Neoplasia. Cancer can cause difficulty breathing by causing fluid to accumulate in the chest cavity, by replacing normal lung tissue with cancerous tissue, or simply by occupying space required by the lungs. Many different types of cancer can occur within the chest cavity.
Pulmonary contusions. Bruising and bleeding into the lungs are the result of trauma and cause difficulty breathing. Pulmonary contusions and pneumothorax are both common following trauma to the chest and must be distinguished from one another by auscultation and chest radiographs.
A diaphragmatic hernia. A tear in the diaphragm, the tissue that separates the chest from the abdominal cavity, allows abdominal organs to move into the chest cavity. A diaphragmatic hernia is often the result of trauma, although some pets may be born with this condition. This problem is diagnosed using X-rays or abdominal ultrasound.
Pneumonia. An infection in the lungs can result from aspiration of vomit or other debris into the airways or can be spread via the bloodstream. Pets with pneumonia often have a fever, which is not typical with a pneumothorax.
In-depth Information on Diagnosis
Your veterinarian may recommend any of the following in order to make a definitive diagnosis:
Chest radiographs are taken to visualize the lungs and the chest cavity. Normally, two X-rays are taken to allow complete assessment. Radiographs are evaluated for the presence of air within the chest cavity, fluid in or around the lungs, or space-occupying lesions in the lungs or chest cavity. The radiographs are also analyzed for the presence of rib fractures, bullae, and chest wall defects, which often accompany pneumothorax resulting from trauma. With pneumothorax, typical X-ray findings include elevation of the heart off the sternum (normally they touch), collapse of the lungs, and inability to follow the edges of the lungs out to the rib cage.
Thoracocentesis is both a diagnostic and therapeutic technique and is performed to remove air from the chest cavity. During this procedure, a local anesthetic is carefully injected into the muscles of the chest wall where the needle will be inserted. A needle is then passed through the chest wall into the chest cavity, and air is removed manually by aspiration with a syringe. In pets that do not have a pneumothorax, no air will be aspirated and negative pressure will be present. In other words, no air can be pulled into the syringe except with great effort and if released, the syringe will spring back to empty.
An arterial blood gas is a test performed to determine the pet’s ability to oxygenate the blood by measuring the amount of arterial blood that is oxygenated. Normally, 95 to 100 percent of arterial blood is oxygenated. In pets with a pneumothorax, the amount of oxygenated blood is much lower. The most common artery for sampling blood is the femoral artery located on the inside of the thigh.
Pulse oximetry is another means to measure a pet’s ability to oxygenate without having to draw blood. A probe is clipped onto the pet’s lip, ear, tongue or skin fold or is inserted into the rectum and, using an infrared light source, detects the level of oxygenated blood. This test is an easier, less stressful means of measuring oxygenated blood in a pet that is having difficulty breathing but, under some circumstances, is not as accurate as an arterial blood gas.
A complete blood count (CBC), is a test that is performed to aid in the overall assessment of a pet’s health when a pneumothorax is present. A CBC helps to identify anemia (low red blood cell count) that may occur due to blood loss following traumatic injuries, and helps to identify high or low white blood cell counts that occur with infection or inflammation.
A biochemistry profile is a blood test that allows evaluation of the internal organs such as the liver or kidneys. In pets that have a pneumothorax from cancer or trauma, this test is particularly important to determine whether the internal organs are affected.
In-depth Information on Treatment