Chronic valve disease (CVD), also known as degenerative valve disease, is the most common cardiac disease in dogs. Its incidence is highest in older smaller breed dogs but can occur in larger breeds as well. As dogs age, the heart valves, that normally control the direction of blood flow, become thickened and nodular for reasons not well understood. As a result, the valve does not close well and develops a leak. The leak causes a vibration of blood that is the source of the murmur we hear with our stethoscope. As the disease progresses over time, the leak becomes bigger, the murmur louder, and eventually the heart begins to enlarge to compensate for the large amount of blood going the wrong direction. The heart can then become so volume overloaded that the pressure inside the heart increases significantly, causing fluid to leak back into the lungs. This is known as pulmonary edema or congestive heart failure. In some circumstances, CVD can also lead to right sided congestive heart failure which usually manifests as a fluid buildup in body cavities such as around the lungs (pleural effusion), in the belly (ascites), or even small volumes around the heart (pericardial effusion). The proper medication regimen can alleviate the signs of congestive heart failure and give your pet a good quality of life at home, but will need to be adjusted as the disease progresses and clinical signs return. Once in congestive heart failure, dogs can survive anywhere from 6 months to 2 years and sometimes longer with the proper follow up, monitoring, and the appropriate medication regime.
Signs your pet may be in congestive heart failure include lethargy, restlessness, difficulty breathing, increased cough, weakness, collapse, fainting, and decreased appetite. If any of these are seen, please seek veterinary attention immediately.