Congestive heart failure leads to inadequate blood flow to the tissues of the body, resulting in lethargy and fatigue. Accumulation of fluid often impairs breathing. When the fluid accumulates in the lungs (pulmonary edema) or around the lungs (pleural effusion), the condition can become life threatening. Though dramatic, the symptoms of congestive heart failure are not specific for only that condition. As there are dozens of reasons for coughing, difficult breathing and fatigue; therefore, your veterinarian will formulate a diagnostic plan to make a correct diagnosis.

The conditions most often confused with heart failure are diseases of the airways, the lung and the chest cavity (pleural space) including:

Tracheal (windpipe) collapse, a common condition in small breed dogs, frequently leads to chronic coughing.

Chronic bronchitis in dogs is an inflammation of the bronchial tree that resembles the smoker's cough of human beings. The cause of most canine cases of bronchitis is not known, but treatment is different than for heart failure.

Pneumonia or infection of the lung can lead to symptoms that are similar to those of heart failure.

Pulmonary fibrosis in dogs is the deposition of scar tissue in the lungs. Symptoms are similar to those of pulmonary edema.

Heartworm disease, a parasitic infection of the blood vessels of the lungs, must be excluded as a possible diagnosis. This infection can also lead to heart failure as well as lung injury.

Tumors of the chest can cause symptoms that resemble those of heart failure.

Fluid accumulation within the chest cavity that surrounds the lungs (pleural effusion) can cause shortness of breath. Some cases are caused by heart failure, but others are not.