Project Summary/ Abstract This R21 application provides a multidisciplinary One Health approach to developing and evaluating a novel Cat Assisted Training (CAT) animal assisted intervention (AAI) for early adolescents with developmental disabilities (DD) and their family cat. The novel CAT intervention will be a 6-week cat walking and training program for youth 10 - 12 years old. Participants will learn how to respond appropriately to cat body language, practice fear-free and positive reinforcement-based handling, and training skills, and how to fit a harness and walk their cats on leash. For the human participants, skills and behaviors learned during the intervention are expected to promote and support long-term physical activity, social wellbeing, and lasting feelings of responsibility even after the intervention itself has concluded. We also expect these experiences to improve the relationship between the child participant and household cat, and in turn, reduce cat stress in the child’s presence and increase cat sociability and indicators of behavioral wellbeing. Because each child will participate with a cat already living in their household, this program will create a unique active partnership between child and cat that considers the health and wellbeing of both partners. Recent pilot work by PIs Udell & MacDonald has revealed physical and social-emotional improvements in children with and without developmental disabilities following a pet dog-partner based AAI. Dogs also showed increased sociability and attachment towards their child partner after AAI participation. Work by PI Udell & Vitale has demonstrated that many cats are highly social and form strong attachment bonds with humans, that cats can be successfully trained a wide range of behaviors, including leash walking, and that cat training classes result in high participant retention rates. Cat social behavior and welfare is also heavily influenced by human behavior and training, making it highly likely that cats would also benefit from this program. There remains a critical need for further empirical evaluation of AAI practices, especially those that target the specific needs of at-risk populations and youth. Further extending the development and evaluation of activity-based AAIs beyond those that include dogs and horses also helps address the critical need to consider and include diverse human participants, creating new equitable opportunities for AAI involvement to those who may have access to cats, but not dogs and horses (due to practical, health, cultural, socio-economic, or other personal reasons).