Pulmonic stenosis is a narrowing or partial obstruction of the pulmonary artery, pulmonary valve, or area of the heart adjacent to the valve that impairs blood flow from the right side of the heart to the lungs. As a result, less blood reaches the lungs, and the heart must pump harder to get blood to the lungs to pick up fresh oxygen. If the narrowing is severe, heart failure may occur because the heart itself is not receiving enough oxygen.
Most young dogs with pulmonic stenosis appear healthy, but, as they age, difficult breathing, tiring on exercise, and fainting may occur. As the condition worsens, signs of heart failure, such as swelling of the abdomen and legs, may develop. Other signs, such as difficult breathing, weakness, and fainting, become more noticeable.
Pulmonic stenosis usually causes heart failure before the dog reaches 3 years of age, but some dogs live a normal life if the stenosis is mild.
Important Points in Treatment
1. In some cases, surgical correction of the stenosis is possible. The doctor will advise you if surgery would be appropriate for your pet. In most instances, treatment is aimed at controlling signs of illness and prolonging life with medical and dietary treatment.
2. Radiographs (x-rays), electrocardiograms (ECG), and laboratory tests are necessary to diagnose the condition and evaluate the response to treatment.