Overview of Hemothorax: Bleeding in the Chest in Dogs
Hemothorax is defined as blood within the chest cavity. The most common cause of hemothorax in dogs is chest trauma, although tumors within the thorax (chest cavity) can also result in a hemothorax if they rupture, slowly bleed or invade into a blood vessel causing blood to accumulate in the thorax. Coagulopathies (clotting disorders) may also cause an animal to bleed within the chest cavity. A hemothorax is usually an emergency situation requiring rapid diagnosis.
What to Watch For
Your dog may take short, shallow, rapid breaths. Look for any observable subcutaneous (under the skin) bruising or evidence of external trauma.
Diagnosis of Hemothorax in Dogs
A thorough history and complete physical exam, emphasizing lung auscultation (listening with a stethoscope), is essential for prompt and accurate diagnosis. Your veterinarian may also recommend:
The above tests are generally the minimum required diagnostic tests needed to obtain a diagnosis. Depending on the animal’s condition, and initial test results, additional tests that may be required include:
Treatment of Hemothorax in Dogs
General approach to treatment varies depending on the clinical condition of the patient.
A hemothorax is generally an emergency situation. Veterinary care should be given as soon as possible. Keep your pet calm and comfortable and minimize stress. Keep your pet warm, and if a traumatic injury is suspected, be careful moving your pet, as fractures may be present.
In-depth Information on Hemothorax
A hemothorax is a potentially life threatening situation. In a normal animal the space between the lungs and the inner chest wall is called the pleural space. This space is more of a potential space, since a vacuum is present and the lungs are always in close contact with the pleural (inner lining) surface of the chest. Thus, as the chest or diaphragm expand, the lungs expand passively as well. If the pleural space becomes filled with blood, there is less room for the lungs to expand and fill with air. Breathing becomes more labored, and less oxygenated blood is distributed to the body. As the volume of blood increases, the ability to breath decreases and rapid intervention is needed.
Rapid blood loss into the chest can also lead to a decrease in blood pressure and tissue perfusion. This may lead to shock. As continued blood is lost, a decrease in circulating red blood cells may lead to acute (sudden) anemia. If veterinary care is not immediately available, rapid blood loss may lead to death. A slower blood loss is more common and will allow for more time to seek veterinary care.
Chronic (long standing) or intermittent blood loss generally occurs more slowly, and more subtle clinical signs might be present. If the blood loss is slow, the body can reabsorb the free blood in the chest. Thus, animals may only have a small amount of blood present in the chest cavity. These animals may not present as an emergency with breathing problems, but they still may have a serious underling disease process. Making the diagnosis of a hemothorax is critical in establishing an underling cause.
If the animal has normal clotting parameters the bleeding into the chest will, many times, stop on it’s own. Blood clots form that stop the bleeding. Blood clots can, however, be dislodged especially with increased movement or manipulations. If blood clots are dislodged, the bleeding may start again. In many cases of hemothorax due to chest trauma, the bleeding will stop on it’s own.
Causes of Blood in the Chest in Dogs
There are several main causes of a hemothorax. Trauma is the most common cause. A lacerated blood vessel within the thorax or pleural lining may lead to rapid or slow bleeding depending on the amount of trauma and the size of the affected vessel or vessels. Outdoor animals are at significantly greater risk then indoor animals. Younger animals are more likely to be injured as well. In young animals with a hemothorax and no history of trauma, a coagulopathy (bleeding disorder) should be suspected. Bleeding into the chest usually does not stop on it’s own, unless vitamin K or other appropriate therapy is administered. In older animals with a hemothorax and no history of trauma, a bleeding tumor within the chest cavity is often the cause. Bleeding tumors may cause a rapid blood loss or be chronic, having intermittent smaller bleeding events. Specific causes of hemothorax include:
One or more of the diagnostic tests described above may be recommended for your dog by your veterinarian. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe.
The following nonspecific (symptomatic) treatments may be applicable to some, but not all pets with hemothorax. These treatments may reduce severity of symptoms or provide relief for your pet. However, nonspecific therapy is not a substitute for treatment of the underlying disease responsible for your pet’s condition. If possible immediate veterinary care should be sought.
A hemothorax may be a life threatening condition requiring immediate intervention. If your veterinarian makes this assessment, time is critical, and immediate thoracentesis may be life saving. Many times, thoracentesis is needed prior to any other diagnostics. Removing the fluid in the chest to improve respiration allows time for the continued diagnostic work up and continued treatment of the patient. Occasionally a chest tube may need to be placed.
A chest tube allows for a more rapid removal of blood from the thorax. The tube needs to be surgically placed and is bandaged around the animals chest. It usually requires sedation or anesthesia. Once in place, the tube can be intermittently suctioned or continuous suction devises may be used. Placing this tube is useful if there is continuous bleeding. Significant amount of chest trauma with additional injuries (pneumothorax), or chronic intermittent bleeding due to a thoracic tumor are instances when chest tube may be needed.
Intravenous fluids are given if there is significant or rapid blood loss. Intravenous fluids maintain blood pressure and improve tissue perfusion. In trauma cases animals are commonly in shock, and have multiple injuries. Fluid therapy is critical in these patients.
Blood transfusions may also be required if there is a significant amount of blood loss causing anemia. Blood loss may be only intrathoracic, or be present elsewhere in the body.
Finally, oxygen therapy may be needed in animals with a large amount of blood in the chest. It is especially useful early in treatment, before or during thoracentesis. Oxygen is administered via oxygen cage, mask or nasal oxygen canula.