From the 23th to 25th of June 2015 Dr. Roberto Santilli gave a course on veterinary arrhythmology in Moscow (Russia). The course was attended by several veterinarians from different cities of the federation. During the lectures we have examined the main heart rhythm disorders of dogs and cats analysing the electrocardiographic appearance, the electrophysiological mechanism and the medical or electrical therapy. The participants showed much interest in the subject. We thank Dr. Maria Nazarova for the great work of simultaneous translation and the Clinic Komodor for hospitality.