Human-animal contact can influence psychological and physiological parameters important to health and welfare; nevertheless, there has been relatively little research on the variables that influence or mediate those health consequences. In addition, little attention has been paid on how to create or alter the animal interactions for the betterment of people and their animals. The investigation can be guided by two theoretical perspectives, which make powerful but different and testable predictions: the biophilia hypothesis and social support theory. Along with this theoretically driven research, there is a need for replication of salient research findings to resolve important discrepancies in the literature. Last, animal-assisted therapy (AAT) has to be placed in the context of alternative therapies now available to define its specificity, risks, and overall benefits.