The organism performs tissue perfusion by developing compensation mechanisms in meeting oxygen demand appearing in various conditions. Cardiovascular system uses very different mechanisms for the oxygen to reach tissues. In athletic animals such as horses, the constitution and usage of these mechanisms are well developed. Physical examination, evaluation of heart rate per minute (HR), peripheral Pulse quality, temperature of the extremities, mucous membrane colors, capillary refill time (CRT), indirect blood pressure, haemoglobuline saturation and blood gas and lactate meaurements are required in the determination of haemodynamic status. Cardiac Output (CO) and cardiac index (CI) are important associate examination methods, giving valuable information in these measurements and in the determination of haemodynamic status, and is measured with various methods in the last decade.