All forms of congenital heart disease occur
in dogs. The most common defects
are valve malformations (called dysplasias),valve narrowing (stenosis),abnormal
openings between the heart chambers (septal defects), patent ductus arteriosus,
and Tetralogy of Fallot.
Patent ductus arteriosusis a persistent arterial connection between the
aorta and pulmonary artery that normally closes at birth or shortly thereafter.
In the uterus, the ductus plays an important role in shunting blood away from