Abstract
The One Health conceptual framework envisions human, animal, and environmental health as interconnected. This framework has achieved remarkable progress in the control of zoonotic diseases, but it commonly neglects the environmental domain, implicitly prioritizes human life over the life of other beings, and fails to consider the political, cultural, social, historical, and economic contexts that shape the health of multispecies collectives. We have developed a novel theoretical framework, Relational One Health, which expands the boundaries of One Health, clearly defines the environmental domain, and provides an avenue for engagement with critical theory. We present a systematic literature review of One Health frameworks to demonstrate the novelty of Relational One Health, and to orient it with respect to other critically-engaged frameworks for One Health. Our results indicate that while Relational One Health complements several earlier frameworks, these other frameworks are either not intended for research, or for narrow sets of research questions. We then demonstrate the utility of Relational One Health for One Health research through case studies in Brazil, Israel, and Ethiopia. Empirical research which is grounded in theory can speak collectively, increasing the impact of individual studies and the field as a whole. One Health is uniquely poised to address several wicked challenges facing the 21st century-climate change, pandemics, neglected zoonoses, and biodiversity collapse-and a unifying theoretical tradition is key to generating the evidence needed to meet these challenges.