Inclusion of polyethox, a medicinal form of high-molecular (4,5 x 10(6) Da) poly(ethylene oxide), into infusion-transfusion therapy of massive hemorrhage (33% of blood volume) in cats leads to an increase in the stroke and cardiac indices, restores antiturbulent and hemorrheological properties of blood, increases systemic oxygen transport, and reduces hypoxic acid-base balance disturbances.