Pulmonic stenosis (PS) is a congenital disease meaning your pet was born with this abnormality. This is a narrowing above, below, or at the level of the pulmonic valve. The pulmonic valve is present in the right heart. This valve allows blood to flow in one direction from the heart to the lungs to get oxygen. When this area is narrowed, the heart has to push harder to get blood through the narrowed area (much like putting your finger over a hose). This causes the heart muscle to thicken so it can generate more pressure to force blood through the small opening. This can occur in any breed but is common in the Boxer, Bulldog, and Boynkin spaniel.
Patients usually present as asymptomatic puppies with heart murmurs. In mild cases, your pet usually has a heart murmur, but will have a normal life expectancy with no restrictions. Moderate cases can be more difficult to predict. Severe cases can develop signs of the disease. Signs include: exercise intolerance, fainting, weakness, collapse, and right sided heart failure commonly manifested as fluid in the belly or ascites. This is diagnosed using echocardiogram, an ultrasound of the heart.
The treatment for dogs with severe disease is a balloon valvuloplasty. This is a procedure performed under general anesthesia with a cardiologist. A balloon is placed using specialized equipment, across the narrowed area and blown up. This is done to relieve the narrowing/stenosis. This procedure is not without risk, but, if successful, can lower the pressure significantly and improve the life span of many dogs. In rare cases, most common in the bulldog, there is an abnormal coronary artery that wraps around the pulmonary artery causing the stenosis (R2A anomaly). This is the one circumstance where balloon valvuloplasty is not recommended. This anomaly is diagnosed under general anesthesia at the time of the balloon procedure using an angiogram. An angiogram is when dye is injected into circulation to visualize the vessels of the heart. If the abnormal coronary artery is seen, the balloon is not performed based on significant risk. Medical management is recommended usually with a beta blocker, to decrease the work of the heart, lower the pressure, and lesson signs or symptoms.