Chronic valvular disease is a degenerative condition that affects the valves of the heart. It is a progressive disease that will worsen over time and can eventually result in congestive heart failure.

Heart valves are designed to act as gates within the heart. They close, allowing blood to fill into the heart chambers prior to the heart muscles “pumping” the blood into the body. They also work to keep blood flowing in one direction throughout the heart and body by preventing the backward flow of blood. With chronic valvular disease, the valves do not function in a normal fashion and allow blood to “leak” through when they are supposed to be closed. The mitral valve is the most commonly affected, and older, small breed dogs are genetically predisposed, including:

• Lhasa apsos
• Toy and miniature poodles
• Yorkshire terriers
• Cocker spaniels
• Chihuahuas
• Cavalier King Charles spaniels
• Miniature schnauzers
• Small mixed-breeds

Symptoms:

Early in the course of the disease, your dog may be symptom-free as his or her body is generally able to compensate for minor decreases in heart function. However, as the disease progresses, you may note:

• Coughing
• Difficulty breathing
• Unable or reluctant to exercise
• Fainting or collapse
• Pale gums
• Decreased appetite
• Lethargy

Diagnostics:

A thorough physical examination, which includes listening to your dog’s heart and lungs, will likely reveal a heart murmur. A heart murmur is a sound that a leaky valve makes. This indicates that a valve is not working properly but doesn’t necessarily mean that chronic valvular disease is present as there are a number of other diseases that can cause heart murmurs, including severe anemia. What it does indicate is that additional evaluation of the heart is warranted. Additional diagnostics include:

• Blood and urine tests
• Chest radiography
• Electrocardiography
• Echocardiography
• Blood pressure measurement

Treatment:

Chronic valvular disease is primarily treated by medical and dietary management. Depending upon the severity, there are a number of medications that can both slow the progression of the disease and improve your pet’s quality of life. A diet low in sodium may also be recommended. Canine valve replacements are still under development in dogs, with only one or two surgical teams worldwide able to perform the procedure at significant cost.

In the event that your pet has progressed to congestive heart failure, hospitalization may be required prior to instituting other therapies.