Phenotypic description of cardiac findings in a population of Dogue de Bordeaux with an emphasis on atrial fibrillation.

•A retrospective review of Dogue de Bordeaux presenting to the cardiology services of two referral hospitals was performed.•Cardiac masses and congenital heart disease, particularly subaortic stenosis, were identified frequently.•The frequency of supraventricular arrhythmia, specifically fast persistent atrial fibrillation, was high.•Atrial fibrillation was inconsistently associated with structural heart disease or cardiac chamber enlargement.•An underlying primary arrhythmic process might be responsible for initiating remodelling in some dogs.