Walking rehabilitation exercise using a robotic dog is proposed. Using a robot instead of an animal in animal assisted therapy overcomes the problems of infection, feeding and excretion, animal abuse, and the like. Patients operate the robotic dog AIBO using an acceleration force sensor, a touch panel, or a center of gravity sensor. Use of these human interface devices allows new functions such as sensing, recording, and processing of human conditions to be easily achieved using information communications technology. One of the key aspects of this proposal is the reversal of the roles of actor and object in assistive technology such as rehabilitation exercises. Patients operate the robot by themselves and the consequent feeling of self-efficacy should help to prolong the rehabilitation exercise. Preliminary experiments conducted at a nursing home and hospital supported this prediction and show the effectiveness of the proposal.