Pulmonic valvular stenosis is a congenital condition wherein the valve did not form properly in utero.

This valve does not open completely and makes the right ventricle work very hard to eject the blood volume.  

Over time, this causes severe hypertrophy (thickening) of the right ventricle. Medications may help reduce this severe gradient.  The recommended surgery for severe disease is a pulmonic 

stenosis balloon valvuloplasty to open the abnormal valve.  

This is an endovascular surgery, where a small incision is made over the jugular vein and the balloon is passed through the blood vessels to the pulmonic valve.  

The goal of this procedure is to reduce the pressure gradient by 50% or more. As long as dogs are within the mild to moderate categories (less than 80mmHg), their quality of life and life expectancy is typically good to excellent.  

Without surgery, patients with severe disease may eventually go into right sided congestive heart failure (fluid accumulation in the belly or thoracic cavity), develop life-threatening arrhythmias, or display weakness or collapse.

In some cases, the pulmonic valve annulus is also reduced (annular hypoplasia), which complicates or limits surgical options.  

In severe cases, it may preclude a surgical option and we must manage these patients with medications alone.

In some breeds, an abnormal right coronary artery (R2A anomaly) can be present, which may make surgery difficult or potentially impossible.  

An angiogram (contrast injected into the blood vessels) is necessary to investigate this prior to the valvuloplasty being performed.