Pet-assisted therapy provides institutionalized individuals with visits from a dog and its handler. Reduction in stress, depression, anxiety and loneliness has all been documented as outcomes of human bonds with therapy animals. The objective of this study is to assess the psychological benefits on nursing home elderly, from receiving regular visits from therapy dogs and human volunteers. Existing literature does not differentiate between the impact on the residents from the pet and the human accompanying the pet. A collaborative effort between Share-A-Pet, a national 501c3 petassisted therapy organization and Nova Southeastern University, will assess the benefits of regular visits provided by therapy dogs and by humans (without dogs), to 100 residents in 10 nursing homes. Studies done in the past have not included comparison (control) groups where the therapy visit was provided by an animal other than a dog or a cat. Study subjects will be evaluated for depression and vital signs before initiation of therapy and at defined intervals for a period of 12 months. We expect a diverse range of demographic, history of pet ownership, physiology, behavior and mood in our study population. All data gathered will be assessed using individual growth curve modeling, an example of a classic random effects regression model commonly used in biomedical research. There is a significant number of elderly who do not want therapy dog visits. If there is no statistically significant difference between our experimental and comparison groups, it will be the first instance of a study that shows it is not the animal, but the visit with its accompanying love and attention, which provides the benefit to the resident. If there is a statistically significant difference between the experimental and comparison groups, this will be the first instance of a pet therapy study done with a comparison group.