Heart failure is a condition, caused by an abnormality in the
structure or the function of the heart, in which it is unable to pump normal quantities of blood to the tissues of the body. The heart is a pump, and when it fails, it often leads to fluid retention in the lung and the body cavities leading to congestive heart failure.
There are many causes of heart failure in dogs, including:
Birth (congenital) defects of the heart
Degeneration of the heart valves
Heart muscle disease (cardiomyopathy)
Heartworm disease
Diseases of the pericardium (the lining around the heart)
Irregular electrical rhythms of the heart (arrhythmia)
Dogs of any age and any breed can develop heart failure. There is certainly a predisposition for heart failure caused by cardiomyopathy in giant canine breeds. Many older, small breed dogs develop heart failure from abnormal function of the heart valves as the valve tissue degenerates.
Heart failure affects your dog by reducing the amount of blood that is pumped to the muscles, leading to fatigue. In addition, most cases of heart failure are associated with the accumulation of fluid in the lungs (pulmonary edema), the chest cavity (pleural effusion), or the abdominal cavity (ascites). This fluid accumulation can lead to shortness of breath and other problems such as coughing and difficult breathing.
What To Watch For
Some of the symptoms of heart failure, and the progression of heart failure in a dog, are related to increased activity of the nervous system and to increased concentrations of circulating hormones (and related chemicals). These include:
Coughing
Shortness of breath
Difficult breathing (dyspnea)
Weight loss
Fatigue
