One Health is a collaborative and multidisciplinary approach to health care that acknowledges how the health of humans is intricately connected to the health of animals, agriculture, and our shared environment. It combines facets of climate change and planetary health with human and veterinary medicine, which is crucial to address health-related challenges within the intersection of these groups (1). At present, there are only a handful of undergraduate medical institutions across the United States that have integrated a One Health approach into their curriculum, educating professional students on these important relationships and encouraging interprofessional collaboration. While the Association of American Veterinary Colleges added One Health to the list of core competencies that all veterinary students should achieve in 2011, the U.S. medical education system is far behind (2). A survey of 133 U.S. medical schools in 2020 found that only 56% included One Health in the curriculum in some form, though the vast majority included in a single lecture or less (3). These authors were able to identify only seven medical institutions throughout the U.S. that offer a dedicated One Health elective or certificate course. This signals a major gap in medical education with an essential need for significant growth (4–6).

The concept of the intersection of human and animal health along with the public health lens is not a novel one and dates to the 19th century (7). This concept grew and developed over the next few decades to eventually be called “One Health.” It is more critical now than ever that medical schools educate students on the vital interconnectedness of human, animal, and environmental health. This is particularly important as the world becomes more connected, and the spread of zoonotic and water-borne diseases continues in a warming planet which leads to changes in animal and human health (8). At the University of Colorado School of Medicine at Colorado State University, the goal of the One Health curriculum is not only to introduce students to the concept, but to create student leaders with an expanded fund of knowledge who are equipped with the tools to incorporate One Health into their future practice and leadership roles as physicians. The course, entitled: One Health Trail: Physician Leaders as Advocates for Human, Animal, and Environmental Health covers an array of topics including but not limited to the modern food supply chain, mining, wildlife and livestock management, water safety and quality, human-animal bonds, planetary and ecosystem health, and healthcare sustainability. Key innovative components of this leadership course include (1) that it is championed by human physician faculty, (2) that in emphasizes collaboration with other healthcare and community professionals, including public health officials, veterinarians, and more, and (3) that it intentionally is grounded in the community in which the course is delivered. This manuscript will provide an overview of the structure of the novel course, discuss in detail the didactic, experiential, and independent learning activities that the students engage in, and subsequently present data to explore the impact of the course on our students. Lastly, the authors will discuss how this course could be translated to other medical education institutions and other graduate programs looking to expand their interdisciplinary curricular offerings in One Health.

The course One Health Trail: Physician Leaders as Advocates for Human, Animal, and Environmental Health was created using a well-structured pedagogical framework that emphasizes the interconnectedness of human, animal, and environmental health. Supported by key references from academic literature and organizational guidelines, the course directors relied on a synthesis of the following pedagogical frameworks and principles: constructivism, transformative learning theory, interdisciplinary and systems thinking, communities of practice, and experiential learning theory.

The constructivist learning approach is based on the principle that students learn best through active engagement and building upon prior knowledge and experiences (9, 10). The learners in this course were 3^rd and 4^th year medical students with a prior foundation in human health and certain One Health topics such as zoonotic disease and antimicrobial resistance. Yet, the students had limited formal engagement with many of the other domains of One Health. Constructivism was applied by utilizing case-based learning and real-world scenarios from our community to allow students to integrate existing knowledge with new environmental and veterinary health concepts. This often led to the use of transformative learning theory which underscores the concept that learning occurs through a shift in perspective, especially when engaging with complex, uncertain, or ethically challenging issues. Shifts in perspective were often noted as students built upon prior knowledge and preconceived notions about certain health challenges or the knowledge base of interdisciplinary experts.

One Health is unique in that it underscores the notion that health challenges are embedded in complex systems and that solutions to those challenges require multi-sectoral understanding and expertise (11). It is therefore essential to include an interdisciplinary and systems-thinking framework in any One Health curricular activity. Systems mapping, root cause analysis, and systems simulation are examples of pedagogical strategies used in the course to apply this framework.

The course directors further relied on the theory of experiential learning which emphasizes that learning is most effective when it involves concrete experience, reflection, conceptualization, and experimentation (12, 13). This was applied to the course by creating opportunities for students to experience One Health in action and to apply learning in new contexts through activities such as site visits and simulations.

Lastly, the course utilized the communities of practice framework which describes the concept that learning occurs through participation in the practices of community or that students learn by “doing” alongside experts (14). This was applied in the course through opportunities to work with professionals from veterinary, public health, and environmental sectors in joint activities. This interprofessional education further mirrors real-life One Health collaboration.

Taken together, the course blended the described pedagogical theories with the goals of promoting knowledge integration and conceptional learning, emphasizing interdisciplinary collaboration and systems literacy, and utilizing applied practice and real-world experiential learning opportunities.

To date, a total of 23 students from the Classes of 2025 and 2026 have participated in multiple different course and immersion evaluations. Among the Class of 2025, 8 students evaluated Immersion 1, and 5 students evaluated Immersion 2. From the Class of 2026, 4 students evaluated Immersion 1, and 6 students evaluated Immersion 2. Following each immersion, all students from both cohorts rated the curriculum on a six-point Likert scale. It is important to note that between the immersions, some students choose to take a year away from the traditional medical school curriculum to pursue research or another advanced degree. A total of 11 students have completed both immersions. Thus, the same number of people do not participate in each immersion.

A critical component of the course involved experiential learning through visits to community-based sites. All students strongly agreed or agreed that the immersion site visits were effective for their learning, and many identified this as the most impactful part of the course. Additionally, 95.7% of students strongly agreed or agreed that they understood the role of public health departments in safeguarding community health. A total of 100% of students reported an improved understanding of the role of organizations such as the CDC in maintaining public health. After Immersion 2, all students (100%) reported increased understanding of the mining industry, its regulatory frameworks, and the interconnections between human, animal, and environmental health. Notably, following a visit to JBS, one of the world’s largest meat processing companies, all students demonstrated an improved understanding of the impact of food production and food safety on human health. One student wrote, “I felt that all the (experiential learning activities) were effective for learning because it helped us to gain community, environmental, and future patient perspectives. I feel this is a particular strength of this trail.”

Reviewing data from the didactic portion of this course, we found that, by the conclusion of Immersion 2, most students had positive experiences. For example, 100% of students in the Class of 2025 and 83.3% of students in the Class of 2026 strongly agreed or agreed that they had gained a clearer understanding of how to incorporate One Health principles into their future medical practice. Additionally, 81.7% of both cohorts reported feeling empowered to address community health challenges through a One Health lens. All students (100%) either strongly agreed or agreed that they felt more confident collaborating with public health professionals to address interdisciplinary health issues. Furthermore, 90% of students from both cohorts indicated that the course improved their understanding of local emergency response systems and health-related frameworks. All students (100%) reported a clear understanding of how human-animal bonds and water quality impact human health. In the Class of 2026, by the end of Immersion 2, 100% of students felt that they had improved understanding of how climate change impacts the ecosystem, as well as human and animal health. Furthermore, 100% of future physicians from the Class of 2026 recognized various methods to advocate for their communities whether it be at bedside, local or national levels. By the end of the course, 81.8% of both cohorts reported an increased ability to generate a clinical differential diagnosis informed by One Health concepts, and 90.9% indicated that the knowledge gained helped them integrate and apply content from other parts of the medical curriculum to improve patient care.

The One Health Trail: Physician Leaders as Advocates for Human, Animal, and Environmental Health offers a practical and impactful approach to integrating the One Health framework into undergraduate medical education. In a world where the interconnectedness of human, animal, and environmental health is increasingly evident, it is imperative to train future physicians to approach patient care holistically. Regardless of specialty, physicians have a responsibility to advocate not only for individual patients but also for the broader systems that influence health.

Physicians are traditionally trained as experts in human biology, disease, and pharmacotherapy. However, understanding external factors, such as zoonotic disease transmission, environmental degradation, water and air quality, and food safety, is essential for comprehensive patient care. The One Health framework empowers medical students to broaden their clinical perspective and critically evaluate health determinants that extend beyond the walls of the hospital or clinic.

Student evaluation data suggests that students who participate in this course develop the skills necessary to identify and address complex health challenges through systems-level thinking. They are introduced to topics and community-based experiences typically encountered later in their careers, such as interprofessional collaboration, environmental health, and public health policy. It should be underscored that integrating One Health into a medical curriculum requires more than adding new content. Instead, it requires bringing together diverse experts who can help medical students see health issues in their full biological, environmental, and social complexity. This was done throughout the course in a variety of ways. For example, a simulated wildfire response exercise with the local department of emergency management, demonstrated to students the importance of multi-disciplinary collaboration to ensure the health of humans, animals, and the environment in the setting of a wildfire. Students come away with the reinforcement that the One Health lens is essential in disaster management. Another example was a visit to a local mine that was led by the actual mining company and workers. Interacting with mine operators and local regulation agency representatives expanded students understanding of the causes, contexts, and solutions of health issues related to mining. This allows a perspective shift from a purely biomedical problem or a disease in a patient to a risk in a system that involves humans, animals, and the environment. Within this framework, students learn to analyze how the health of patients, animals, and their shared environments interact to influence clinical outcomes.

Capstone projects highlight the application of One Health principles in diverse contexts. For example, one student explored food security through a One Health lens, analyzing the roles of various stakeholders in ensuring sustainable and equitable access to safe food and clean water for both people and animals. Another student examined cross-disciplinary collaboration between physicians and veterinarians—proposing ways to integrate techniques from adult and pediatric medicine, such as Advanced Trauma Life Support (ATLS), into veterinary practice, and vice versa. They noted, for instance, how insights from veterinary medicine, like the progression of joint disease in animals, could inform preventive strategies in human medicine. Students also learned how to provide empathetic, culturally sensitive care, particularly for Indigenous communities whose relationships with animals and the environment are central to their identity and well-being. These experiences helped students confront and understand the social injustices embedded in health systems and consider how One Health-oriented solutions might contribute to more equitable care.

From the perspective of course directors, key lessons have emerged from working with the first two cohorts. First, community-based experiences are essential. Both subjective and objective data show that students gain a deeper understanding of the social and environmental determinants of health through immersive, real-world engagement. These opportunities prepare them to advocate effectively for community-driven solutions. Second, teaching students to analyze health issues through a One Health lens encourages long-term, sustainable thinking. Solutions developed in this way often have broader and more lasting impacts across multiple generations.

Feedback from students was largely positive with one student commenting that they felt like all medical students should be required to take this course. A few students commented that the work load was larger than what they had expected and that engagement in the community sometimes lead to long drives that were time-consuming. That being said, students consistently preferred experiential learning over traditional classroom didactics. These community-engaged, interdisciplinary approaches are not only more memorable but are likely to have a lasting influence on students’ clinical practice and advocacy efforts as they enter the healthcare workforce. As course directors, we advocate that the content addressed in this novel curriculum be adapted and incorporated into all U.S. medical schools.

This curriculum and its associated data collection have limitations. Most notably, the current evaluation is based on a small cohort of students, which limits the generalizability of findings. There is also a potential selection bias, as students who choose to take this course may already have an inherent interest in One Health concepts. Additionally, while the course content was designed to be broadly applicable to medical practice across diverse settings, some elements are inherently region-specific. For example, collaboration with the local public health department on wildfire emergency preparedness is highly relevant in Colorado but may be less applicable in regions such as Florida. Nevertheless, the underlying competencies—such as disaster preparedness and interagency collaboration—are transferable and can be adapted to other environmental contexts. Other medical schools seeking to integrate this curriculum at their campus could adopt content applicable to all learners regardless of geographic location, such as pandemic prevention, human-animal bond, or climate change, and then also work with their own local policymakers, non-profits, academic experts, and community-based organizations to integrate local, community-specific One Health challenges to the course. In this way, the course is highly adaptable across different institutions for undergraduate medical education.

As the program continues, it is expected that larger student cohorts and ongoing evaluation will strengthen the data set and inform iterative improvements to the curriculum. Despite these limitations, the One Health Trail represents a valuable and adaptable model for integrating One Health principles into medical education. With minor modifications to reflect local environmental and public health priorities, this curriculum could be implemented effectively at other medical schools, both nationally and internationally.