Human welfare, social welfare, and animal welfare have traditionally been seen as distinct disciplines. Human welfare deals with the mental state of individuals, social welfare deals with the balance of welfare across societies and generations, and animal welfare deals with the physical and mental well-being of the animal species we use for pleasure, labor, or food.

We pose that the separation between human, social, and animal welfare is an artificial compartmentalization. These disciplines rely on the same set of scientific measures and heavily depend on each other in an ecological context. Their study, therefore, requires a broader, interdisciplinary approach. We believe this would allow development of a new, evolving discipline that can address mounting welfare challenges and opportunities through an unparalleled framework for action and also create an exciting path for veterinary medicine, specifically in advancing human society.

The one health movement acknowledges the interconnectedness of human, animal, and environmental health and the necessity for an interdisciplinary approach in these fields. Other scientific fields, such as environmental science and conservation ecology, have also embraced a broad interdisciplinary approach to define and solve the problems confronting their fields,^1,2 and we believe that the field of animal welfare could benefit from a similar approach inspired by these movements. We propose, therefore, embracing the concept of connecting human welfare and social welfare to the diverse body of what is now considered animal welfare. In short, we propose embracing the concept of one welfare.

Welfare is a nascent, exciting field that asks us to confront the most contentious and important questions of ethics, science, production, health, economics, and politics.³ We should no longer seek to make welfare decisions in isolated disciplines or to work on unconnected pieces of the puzzle. Rather, we should make decisions in an interdisciplinary frame with a focus on action and a mission of balancing and promoting human and animal welfare in connected ecosystems and societies.⁴

Animal and human welfare are intrinsically interconnected, and animal welfare specialists have long noted situations in which animal welfare is clearly tied to human welfare. In addition, known and supposed tradeoffs in human and animal welfare create contentious problems. For example, improving agricultural animal welfare may decrease human welfare by increasing the cost of food in society, raising ethical questions about tradeoffs between human and animal well-being. Such concerns warrant investigation, particularly given the current pressures on the global food supply as the increased demand for animal protein raises environmental and biodiversity concerns. In a global economy where animal welfare policy decisions in one country can impact food costs, wildlife habitats, and energy consumption across multiple nations, these concerns can no longer be addressed without a broader vision.⁵ They also must not be addressed without ensuring that changes meant to improve animal welfare do not result in a net decrease in welfare in humans or other populations of animals. Animal welfare practitioners must consider the impact of these connections to design comprehensive solutions that produce desirable societal outcomes internationally.

We believe that an interdisciplinary approach to human, animal, and social welfare is critical to further progress in welfare science. A one welfare approach will directly bolster connections and comparisons between animal and human welfare. It will foster collaboration between related disciplines and inform approaches that stimulate action and civic engagement.⁶ This multifaceted approach may also engage new fields that would provide additional perspectives. Considering the question of agricultural animal welfare and food costs, an interdisciplinary approach could help better define the problems, identify relevant data, and devise solutions. Evolutionary geneticists, behavioral ecologists, and neuroscientists could help elucidate the emotional and sentience capabilities of other animals, compared with humans.⁷ Economists could help identify and compare opportunity costs and impacts on consumers and trade.⁸ Economic analyses could help quantitatively compare the financial costs of various welfare approaches with the benefits gained in regard to animal and human welfare.⁹ Environmental scientists could help quantify the implications of various production system changes, particularly as they relate to human and wildlife welfare. Social scientists could help study the adoption of various policy decisions across political boundaries to help understand the political landscape of the animal welfare debate.¹⁰ Public administration professionals could help fine-tune program implementation strategies for various animal welfare policies, and education specialists could address the best methods for conveying knowledge to those people who need it most. Finally, the networking capacity of a one welfare approach could empower the animal welfare field to more effectively address the connections between science and policy in various areas of human society.^11–13 A one welfare approach recognizes the clear interdependence between related fields, which we believe would be of benefit at every level, from the initial identification of a problem through the implementation of a solution.

Global ethical and policy decisions about human and animal welfare should be based on considerations of the well-being of animals and humans within their ecosystem. Well-being can be measured for humans and animals, creating a scientific foundation for such decision making.^14–16 Furthermore, solutions across industries, societies, and cultures can be compared and characterized scientifically as they relate to welfare. Even with incomplete data, science's influence on policy solutions to social problems such as animal welfare can be potent.¹⁷ Simply, objective welfare measures can be used to identify situations whereby the welfare of one group of animals is improved without decreasing the welfare of other groups. In more complex situations, objective animal welfare measures can be used to inform debates about tradeoffs between conflicting interests representing different social, ethical, and political viewpoints.

The veterinary profession's mission is tied to human and social welfare and resonates with the one welfare concept. Our profession was founded to protect the health of animals used for human needs such as work, war, and food.¹⁸ From the beginning, therefore, veterinarians have had a responsibility to promote human well-being alongside animal well-being. Today, this mission continues: companion animal veterinarians promote the human-animal bond, regulatory veterinarians guard public health and ensure a safe food supply for humans and animals alike, and veterinary researchers work at the interface of human and animal health and welfare. There are countless examples, but it is clear the veterinary profession is driven toward promoting human well-being alongside animal well-being.¹⁹ The one welfare concept embodies this mission.

The one welfare concept also offers a timely expansion of opportunities for veterinarians. A recent National Academy of Sciences report²⁰ highlighted the growing societal need for veterinary leadership in new and emerging fields related to ecosystems, public health, and global ecology. It also highlighted the need for a sustainable investment in these nontraditional competencies. Recognizing the interconnectedness of human, social, and animal welfare will highlight the changing role of veterinarians in the animal welfare and public service disciplines and allow veterinarians to assume roles in arenas not traditionally associated with veterinary medicine. A one welfare approach could help catalyze networking in scientific policy creation, expanding a role that organized veterinary medicine already assumes to some degree.^21,22 In essence, the one welfare approach offers a new vision to address social challenges, and the veterinary profession would do well to spearhead this movement.

At the dawn of agriculture 10,000 years ago, humans and domesticated animals comprised approximately 0.1% of the vertebrate mass on land. Today, that figure is closer to 98%. As stated by Paul MacCready,²³ “Over billions of years, on a unique sphere, chance has painted a thin covering of life—complex, improbable, wonderful, and fragile. Suddenly we humans (a recently arrived species no longer subject to the checks and balances inherent in nature) have grown in population, technology, and intelligence to a position of terrible power: we now wield the paintbrush.” As society tries to manage this power, veterinarians are on the forefront as guardians of the health and welfare of animals and the public. Our profession's mission is particularly awe inspiring in this view. We have already recognized the power of interdisciplinary and international approaches to complex issues. In adopting the concept of one welfare, the veterinary profession can grasp an expanded capacity to enhance human and animal well-being across the biological ecosystem in which we coexist.