OBJECTIVES: To evaluate the occurrence of aortic stenosis and establish echocardiographic reference values in the Dogue de Bordeaux in Denmark. METHODS: Fifty-three dogs were auscultated for evidence of a cardiac murmur and a full echocardiographic examination was performed. The criterion for the diagnosis of aortic stenosis was a peak aortic velocity greater than 2.5 m/s from a subcostal transducer location. RESULTS: A left-basilar ejection murmur was detected in 38 (72 per cent) of the dogs. An aortic ejection velocity greater than 2.5 m/s was identified in 9 (17 per cent) of the dogs from a subcostal view. The aortic annulus in Dogue de Bordeaux was smaller than that considered normal in other breeds with comparable body size. Furthermore, a decreased aortoseptal angle was noticed in dogs with aortic stenosis. CLINICAL SIGNIFICANCE: The Dogue de Bordeaux may be highly predisposed to aortic stenosis. The small aortic annulus noted in healthy and affected Dogue de Bordeaux and a decreased aortoseptal angle noted in affected dogs in this study might reflect key aetiological features in the development of aortic stenosis.