Atrial septal defect

is it a genetic problem in cattle?

Abstract

This study was designed to determine the time sequence of postnatal changes associated with the atrial septum in the bovine heart, and to assess if atrial septal defect (ASD) is a genetic disorder in stillborn Maine-Anjou calves. The study was divided into three parts: (1) review of the necropsy database; (2) examination of hearts from "normal" Holstein-Friesian calves; and (3) examination of hearts from stillborn beef calves and cattle dying of unknown cause. In the normal Holstein-Friesian calf the opening in the atrial septum is covered completely by a membrane at birth, resulting in an anatomic but not a physiologic opening, and closes completely between seven and 14 days of age. The same time sequence appears true for hearts from beef calves. Of the 27 hearts from beef cattle examined, six bull calves (three purebred Maine-Anjou, two Maine cross, one Shorthorn) and one 18-month-old Maine cross heifer had an ASD, which included both an opening in the atrial septum and an abnormal membrane. ASD is likely a genetic disorder of cattle, which may have a greater gene frequency in the Maine-Anjou breed.