Prevalence of arrhythmias in dogs examined at the Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia (2018-2020)

The aim of this retrospective study was to determine the prevalence of arrhythmias in dogs admitted to the Clinic for Internal Diseases, Faculty of Veterinary Medicine, University of Zagreb, Croatia. Medical records of 307 dogs that underwent electrocardiographic examination between October 2018 and October 2020 were analysed. The study population (65 breeds, median age 9 years, median body weight 15 kg) showed arrhythmias in 36.2% of cases. The most common arrhythmia was atrial fibrillation (18% of the total population; 26.7% of dogs with heart disease), followed by premature ventricular and atrial contractions. Arrhythmias were also detected in 18.6% of dogs without primary cardiac disease, most often associated with systemic disorders such as tumours, epilepsy, hypoadrenocorticism and arterial hypertension. The results confirm that arrhythmias are frequent in dogs, occurring both in the presence of heart disease and as a consequence of non-cardiac conditions, emphasising the importance of routine electrocardiographic screening in veterinary clinical practice.