Pulmonary Congestion in Dogs

When a dog coughs, usually it's a sign of cold or seasonal allergies, conditions that can be easily treated. However, if the animal develops a deep, hacking cough that continues over a longer period of time, a veterinarian may diagnose pulmonary congestion related to other diseases in the dog's body and the treatment might be prolonged and difficult.

  1. Significance

    • Pulmonary congestion in dogs refers to a disease process where the walls and vascular tissue of the lungs become engorged with blood. Lung congestion normally precedes pulmonary edema---an accumulation of fluid in the functional spaces of the lungs and the alveoli (tiny sacs found at the end of the lung's bronchi). When this condition occurs, air space in the lungs is compromised and respiratory distress can develop.

    Causes

    • The most common cause of pulmonary congestion in dogs is congestive heart failure. When the valves of the dog's heart do not function well enough to allow sufficient flow of blood from one valve to the other, the blood will backup through the veins back to the lungs and into the vascular tissue. Traumatic injury can also cause lung congestion, particularly if bruising occurs in the body area around the lungs. Heartworm disease, drug toxicities, infection or enlargement of the heart muscle, and severe allergic bronchitis can also result in pulmonary congestion.

    Disease Symptoms

    • The symptoms of pulmonary congestion are closely related to the symptoms of heart failure. A diseased dog may have a cough that worsens at night and resonates deep within the chest. The dog may show signs of exercise intolerance, be weak and lethargic, and have fainting spells. They may be unable or unwilling to eat. Dogs often develop difficulty breathing, especially when lying down and heart arrhythmias are common.

    Treatment

    • Veterinarians will commonly place dogs with lung congestion on diuretics to increase urine output and allow some of the fluid to be processed by the kidneys and pass out of the body. The dog may also be given drug treatment to increase heart function and regulate heart arrhythmias. If fluid is found in the lung spaces and the dog is in respiratory distress, a needle may be introduced into the cavity and the liquid drawn off into a syringe. Vets may also recommend a sodium-restricted diet and little to no exercise.

    Considerations

    • Pulmonary congestion in a dog is a serious condition and can be life threatening. Immediate veterinary care is necessary, and even with treatment, some dogs do not survive. If heart disease is the underlying cause for the congestion, treatment may become palliative---decreasing fluid accumulation in the lungs and increasing cardiac output so that the dog is more comfortable. Because of the high mortality rate of congested dogs with heart problems, quality of life is usually the prime consideration for both veterinary professionals and pet owners and euthanasia becomes an option.