Relevance. The study of the pathogenesis of obesity in domestic animals is an urgent problem in veterinary medicine, which is associated with the high prevalence of this pathological condition and a significant risk of complications from the cardiovascular system. The aim of the study was to present the pathophysiological characteristics of the development of arterial hypertension syndrome in obesity in Yorkshire Terrier dogs.Methods. In a comparative aspect, clinical, tonometric, electrocardiographic, echocardiographic and biochemical parameters were studied in obese patients (n = 13) and clinically healthy dogs (n = 7).Results. Our study shows the negative role of obesity in the development of arterial hypertension syndrome in Yorkshire Terrier dogs. It was also found that obesity in dogs is accompanied by impaired lipid metabolism, oxidative stress, the development of arterial hypertension and a tendency to the development of concentric hypertrophy of the left ventricular myocardium and hepatopathy.