To examine the potential role of companion animals as sentinels of relevant, shared environmental exposures that may affect human aging and cancer, the National Cancer Policy Forum held a workshop in collaboration with the Forum on Aging, Disability, and Independence and the Standing Committee on the Use of Emerging Science for Environmental Health Decisions to explore this promising and underutilized pathway for research. Presentations and panel discussions covered the current state of the science and pathways for accelerating research, along with opportunities and challenges for using this novel translational approach to exposure science to advance human health. This Proceedings of a Workshop outlines the presentations and discussions that occurred during the workshop.