On Sunday, 17 September 2017, a seminar on ventricular arrhythmias in the dog was held in Milan at the UNISVET Headquarters. The speakers of the day were Dr. Roberto Santilli (Associate Professor of Cardiology at Cornell University, NY, USA and Head of Cardiology Unit of the Malpensa Veterinary Clinic and Veterinary Hospital I Portoni Rossi) and Dr. Manuela Perego ( operative at the entrances operative units of cardiology of the Veterinary Clinic Malpensa and of the Hospital I Portoni Rossi). The day began with a review of electrocardiographic characteristics of the ventricular arrhythmias of the dog with related electrophysiological mechanisms. Relationships on the various pathologies commonly induced ventricular arrhythmias in the dog such as arrythmogenic cardiomyopathy, dilated cardiomyopathy, myocarditis, chronic mitral valve disorders, and extra-systemic disorders have been reported. The day ended with the analysis of family ventricular arrhythmias and the acute and chronic therapy of these rhythm disorders.