Isoproterenol hydrochloride and lactated Ringer's solution were employed in the treatment of low perfusion acidosis produced by acute blood volume reduction in 27 dogs. Their relative effectiveness was determined by measuring oxygen consumption, cardiac rate and output, and blood pressure. Neither isoproterenol nor lactated Ringer's solution produced significant improvement in either cardiac function or oxygen uptake. Significant improvement did, however, result when lactated Ringer's solution and isoproterenol were used in combination.