The aim of the study was to analyze the adaptation of the cardiovascular system of service dogs to the loads of the search and rescue profile, based on the data of echo and electrocardiographic studies. The study included clinically healthy dogs of medium breeds of the search and canine service, divided into two groups. The animals of the first group participated in the normalized, and the animals of the second group in the non-normalized search and rescue operations. There were 10 animals in each group that had no significant health abnormalities according to the clinical examination. EchoCG was performed on the Mindray DC-8 Exp device using a sector phased and microconvex sensor. The ECG was recorded using a Poly-Spektr-8/V device using the standard lead method, and the ECG was taken within five minutes. The statistical analysis of the obtained data was performed in the Microsoft Excel 2016 program. As a result of the research, it was found that the participation of medium-breed dogs in prolonged PSR of any type leads to changes in echocardiographic and electrocardiographic parameters, which is due to the forced adaptation of the cardiovascular system to increased stress. After participating in long-term non-normalized PSR, they showed a significant increase in the values of the final systolic size (DAC) and the final diastolic size of the CDR, an increase in heart rate (HR), shortening fraction, amplitude of the Q, R and T waves, QT/TQ ratio, PQ interval, aortic diameter, against the background of a decrease in the numerical value the electrical axis of the heart (EOS). At the same time, the increases in the thickness of the interventricular septum (IVP) and the posterior wall of the left ventricle (LVL) revealed in the second group indicate a tendency towards the development of concentric hypertrophy of the left ventricle (LV) and are an indication for regular EchoCG in animals participating in prolonged abnormal PSR, necessary for the timely detection of secondary cardiovascular disorders.