Lung Lobe Torsion in Dogs
Torsion, or twisting, of the lung lobe results in the obstruction of the dog's bronchus and vessels, including the veins and arteries. The obstruction of the blood vessels causes the lung lobe to engorge with blood, which results in necrosis and death of the affected lung tissue. This may lead to many complications, including coughing up blood, tachycardia, or shock.
Male dogs are at a higher risk of lung lobe torsion than females, as are large, deep-chested. However, small dogs such as pugs (especially those younger than four) are also at risk, most often with the spontaneous form of lung lobe torsion.
Symptoms and Types
- Loss of appetite (anorexia)
- Coughing (sometimes with blood)
- Difficulty breathing, especially while lying flat (orthopenea)
- Increased respiration rate
- Coughing up blood
- Increased heart rate
- Pale or bluish mucous membranes (cyanosis)
Lung lobe torsion is inconsistently found with pre-existing conditions such as trauma, neoplasia, and chylothorax. However it also occurs spontaneously, due to a thoracic or diaphragmatic surgery, or, on occasion, due to an unknown cause (idiopathic).
You will need to give a thorough history of your dog’s health, including the onset and nature of the symptoms, to your veterinarian. He or she will then perform a complete physical examination as well as a biochemistry profile, urinalysis, and complete blood count (CBC). These tests may reveal valuable information for initial diagnosis and may show signs of infection, anemia. It will also reveal the level of immune response of your dog. If the number of white blood cells is abnormally lower than the minimum normal range, the prognosis is very poor.
Your dog’s veterinarian may decide to take a small sample of the accumulated fluid for further evaluation, while ultrasound, computed tomography, and radiographic studies often reveal more details about the problem. Loss of normal architecture and blood vessels, along with opacification of the affected lung are usually seen in an X-ray.
In some cases, surgery is required for definitive diagnosis and treatment.
Your dog may need to be hospitalized for intensive care and treatment, especially if surgery is required, which is often the treatment of choice to remove the affected lobe and correct other abnormalities. If abnormal fluid or blood is present, your veterinarian will place a chest tube to allow for drainage. If your dog is not able to breathe normally, ventilator support is given to assist in breathing. Oxygen therapy, fluids, and antibiotics are also typically added to treatment protocol. And if the dog survives, shrinking and fibrosis of the affected lobe will be seen.
Living and Management
After surgery, your dog may feel sore and need pain killers, as well as cage rest, for a few days. However, most animals recover fully after a successful operation. The chest tube is often kept in for a few days to allow drainage of fluid. Your veterinarian will describe the proper handling of this tube. If you see any untoward symptoms, including breathing problems, immediately call your dog’s veterinarian. Otherwise, follow his or her instructions and bring the dog in for regular examinations.