Abstract
A dairy cow with prostration, anorexia, and arrhythmia during the periparturient period was cardiographically diagnosed as having complete atrioventricular block. Macroscopically, the heart was round and moderately enlarged. Histopathologically, fibrous tissue was markedly proliferated around vessels from endocardium to stratum myocardium. We diagnosed this as a case of endocardial fibrosis with complete atrioventricular block.
