Pulmonic stenosis is the second most common
congenital heart defect in dogs. This diagram
shows three different types of pulmonic stenosis. There is a valvular type with commisural fusion, an
immediately
sub-valvular fibrous type,
and infundibular type in which there
is severe primary right ventricular hypertrophy (RVH). The first two types have
secondary RVH.