Atrial Natriuretic Peptide (ANP) is mainly released from atrial myocytes in response to an increase in right or left atrial pressure. Brain Natriuretic Peptide (BNP) is secreted predominantly by left ventricular myocytes secondary to volume expansion or pressure overload. The aim of this study was to evaluate the diagnostic accuracy of plasma level of both cardiac natriuretic peptides to detect asymptomatic left ventricular alterations in a dog model of dilated cardiomyopathy, i.e., the Golden Retriever Muscular Dystrophy (GRMD). GRMD cardiomyopathy is related to a spontaneous X-linked mutation of dystrophin gene, and is characterized by myocardial necrosis, mineralization and fibrosis, leading to late progressive left ventricular dysfunction and then heart failure.[-]