Results: Compared with the control group, patients visited by a volunteer-dog team showed significantly greater decreases in pulmonary artery pressure during (5.34, P = .003) and after (5.78, P = .001) the intervention, pulmonary capillary wedge pressure during (3.09, P = .02) and after (4.31, P = .002) the intervention, and epinephrine (17.54, P = .04) and norepinephrine (240.14, P = .02) levels during the intervention. After the intervention, patients visited by the volunteer-dog team showed the greatest decrease in state anxiety over patients visited by a volunteer only (6.65, P = .003) and the control group (9.13, P < .0001).