One health ethics: “What then must we do?”

One Health, as proclaimed by the United Nations Quadripartite, is “an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals, and ecosystems.” As such, it recognizes that the health of people, other animals, and nature is closely linked and interdependent. A great deal of One Health education, research, and practice is grounded in science, while ethical considerations are addressed infrequently. Yet ethical issues are inherent to each stage of One Health. They include which aspects of interdependencies to study, how to extend health and well-being beyond humans, and what trade-offs to consider when optimizing the health of people, other animals, and nature. In this article, we call for an active debate on the ethical considerations that should underpin every stage of One Health. We propose four tenets for discussion that, if adopted, could serve as springboards from which to consider how we “ought” to teach, investigate, and practice One Health.