What is One Health? “One Health” is the recognition that human, animal, plant, and environmental health are interconnected and interdependent. Therefore, communication and collaboration across agencies and disciplines is necessary to improve health outcomes for all. History While the term “One Health” did not come into use until the early 2000s, the idea it represents is not new, for example the reciprocal relationship between humans and the natural world is a core belief of many Indigenous peoples. During the 19th century pathologists such as Dr. Rudolf Virchow and Dr. William Osler advocated for linkages between human and animal medicine, later known as “One Medicine.” In 2004, the Wildlife Conservation Society hosted a symposium on “One World – One Health” resulting in the “Manhattan Principles,” a series of 12 recommendations for establishing a more holistic approach to disease prevention and preservation of ecosystems. Since then, many groups including governments, international agencies, and universities have invested in One Health collaborations as a critical foundation to address many of our most pressing issues. A formal definition for “One Health” was authored in 2022 by the One Health High-Level Expert Panel (OHHLEP), a joint advisory group for the Food and Agriculture Organization of the United Nations (FAO), United Nations Environment Programme (UNEP), World Health Organization (WHO) and World Organization for Animal Health (WOAH). This definition states: “One Health is an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals, and ecosystems. It recognizes the health of humans, domestic and wild animals, plants, and the wider environment (including ecosystems) are closely linked and interdependent.” One Health Issues Examples of issues that benefit from an interdisciplinary One Health approach: