Behavioral disorders are considered risk factors for relinquishment of pet dogs and cats to shelters. While acupuncture may be a safe and effective treatment option, there is little in the scientific literature to support its use. There are, however, several reports in human medicine on the use of acupuncture to treat a variety of emotional disturbances, as well as animal model research that has revealed some of the physiologic mechanisms that may play a role in the ability of acupuncture to alter human and animal behavior. Results from human studies have been mixed, in part because studies involving acupuncture are difficult to design. Laboratory animal studies have clearly demonstrated that acupuncture modulates the chemical environment of the central nervous system and its function. Behavioral disorders in companion animals have previously been linked to environmental factors, but the recent focus has been on identifying biochemical abnormalities that may contribute to abnormal behavior. From the TCVM perspective, companion animals frequently present with Shen disturbance, which manifests as anxiety, irritability and hyperactivity. The Shen is housed in the Heart, therefore disturbances of the flow of Blood in the Heart often lead to Shen disturbance. Because reports on the use of acupuncture for companion animal behavioral problems are scarce, further clinical studies are needed to elucidate the mechanisms of how acupuncture affects mood and behavior in companion animals and to determine optimal acupuncture protocols.