Animal Welfare as an Essential Element of One Health

Abstract

Animal welfare is a crucial component of the One Health principle, which the World Health Organization (WHO) describes as “an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals, and ecosystems. It recognizes that the health of humans, domestic and wild animals, plants, and the wider environment (including ecosystems) are closely linked and interdependent.” (WHO, 2025) [1].

The relationship between humans and animals is multifaceted, encompassing emotional, economic, and social dimensions. Companion animals, such as dogs and cats, provide emotional support and improve mental health, reducing stress and loneliness. Working animals, such as horses and oxen, are indispensable in many agricultural communities, aiding in transportation and farming tasks. Ensuring their welfare directly impacts human livelihoods and economic stability. Perhaps the biggest area of human–animal interrelationship is in agriculture, where 92 billion land animals are produced worldwide every year for food.

Ensuring the well-being of animals is essential for several reasons. Firstly, animals can act as reservoirs for pathogens that may transmit to humans, leading to zoonotic diseases. By prioritizing animal welfare, we can reduce the risk of disease transmission and safeguard public health. Healthy animals are more resilient to infections, which minimizes the spread of diseases within animal populations and reduces the need for antimicrobial interventions.

This is particularly important in the context of antimicrobial resistance (AMR), a growing global health threat. Nearly three-quarters of all the world's antibiotics are fed to farmed animals, largely to control diseases inherent in the cramped, squalid conditions of industrial animal agriculture. This is a major reason for the WHO to warn that action is needed if we are to avoid a post-antibiotic era, where diseases that are currently treatable could once again kill. Experts suggest that by the middle of the century, the demise of antibiotics could lead to about 10 million deaths a year [2, 3].

More than 60% of new and emerging infectious diseases that threaten human health originate in animal populations. These threats are significantly increasing in frequency and severity over time, with tremendous long-term impacts [4].

COVID-19 is the latest example of a major pandemic caused by a zoonotic pathogen. However, there are many other zoonoses, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS-CoV), zoonotic influenza (H5N1, H7N9, H1N1), Zika, and Ebola virus diseases, which have or could potentially cause epidemics in humans.

The traditional single health system has not been effective at addressing these challenges. Outbreaks of infectious diseases in different species and regions not only pose a serious threat to human and animal health and survival but also cause huge economic losses. In addition, the incidence of foodborne disease continues to increase and has become another public health crisis that cannot be ignored.

The ethical treatment of animals reflects our societal values and moral responsibilities. As sentient beings, animals deserve to live free from suffering. This ethical stance is not only a moral obligation but also fosters a culture of empathy and compassion, which can extend to human interactions and societal norms.

Animal welfare is about ensuring the well-being of the individual animal. This involves the physical and mental well-being of the animal, as well as allowing for the expression of normal behaviors.

The welfare of an animal, therefore, can be described as good or high if the individual is fit, healthy, and happy.

Truly high animal welfare is more than the absence of suffering: It should allow animals to enjoy positive experiences summed up in the phrase, the joy of life.

The ethical treatment of animals in agriculture can enhance the quality, safety, health, and nutritional qualities of the food for consumers.

Truly high standards of animal welfare also support biodiversity conservation by protecting wildlife and their habitats. Healthy wildlife populations contribute to balanced ecosystems, which provide essential services, such as pollination, water purification, and climate regulation. Protecting animal welfare through nature-positive, high animal welfare farming practices ensures the stability and resilience of these ecosystems, which are crucial for the overall health of our planet.

Animal welfare is, therefore, integral to the One Health approach, as it promotes the health and well-being of all species, supports sustainable food production, and helps prevent the spread of infectious diseases.

The One Health concept has deep roots in ancient Chinese philosophy. Early in the Warring States period (475–221 BCE), Taoism believed that man and nature have the same origin and advocated for the peaceful coexistence of humans and nature [5]. It promoted treating humans, animals, plants, and the environment as a single entity for sustainable development, forming the cultural origin of China’s One Health development.

Clearly then, One Health is not new, but has become more important in recent years. This is because many factors have changed the interactions between people, animals, and our environment.

The way we produce and consume food represents the biggest single interaction between humans and animals, meaning that food systems are of the utmost importance to any consideration of One Health.

Global agrifood systems are now recognized as having a huge role to play in solving the existential threats now facing humanity from climate change, biodiversity loss, pollution, and growing health challenges.

This recognition is particularly clear through the shift in narrative enshrined at the UN Food Systems Summit of 2021, where many of the world's governments committed to taking action to transform the way we produce and consume food.

This was further deepened in 2023 at the climate negotiations in Dubai under the UN Framework Convention on Climate Change (UNFCCC), which placed food system transformation firmly on the agenda. The UAE Declaration on Sustainable Agriculture, Resilient Food Systems, and Climate Action, signed by 134 heads of state at COP28, saw governments commit to “Revisit or orient policies and public support related to agriculture and food systems to promote activities which increase incomes, reduce greenhouse gas emissions, and bolster resilience, productivity, livelihoods, nutrition, water efficiency and human, animal and ecosystem health while reducing food loss and waste, and ecosystem loss and degradation.” [6].

A successful transition toward sustainable, inclusive, and resilient food systems that could deliver a livable and equitable future for all people, animals, and the planet involves moving away from unhealthy and environmentally harmful agricultural practices, including industrial animal agriculture.

There should be a transition toward sustainable food systems based on nature-positive practices, such as agroecological and regenerative farming, with its primary aim of feeding people with healthy, nutritious food while protecting soil health and improving animal welfare.

Animal welfare must be seen as a key element of future-fit food systems and an essential metric of how successful we are being at moving toward the achievement of goals relating to sustainable development.

The most optimal transition is to move to farming practices that no longer confine animals to cages, crates, and confinement; instead, restore animals to the countryside as part of mixed, rotational, agroecological, and regenerative farming. This provides scope for multiple health, environmental, and animal welfare benefits through farming in harmony with nature. Embracing farming systems based not on cruelty, extraction, and decline, but on putting back into nature's bank account. Respecting the welfare of animals and their wants, needs, and feelings.

Over the last 35 years, I have made it a professional priority to see as many different types of animal farming as possible, including those industrial farms that are harmful to animal health and welfare.

Industrial animal agriculture, or “factory” farming, involves hundreds, thousands, and sometimes tens of thousands of sentient creatures crowded together in barren and darkened barns, with many suffering in barren cages. Egg-laying hens, for example, are in cages too small to flap their wings. Pregnant pigs are often in crates where they cannot turn around for weeks or months at a time. Cows are kept in large numbers in grassless feedlots where they are fed grain instead of their natural diet of grass. Migratory salmon infested with lice and sores, in a sea cage with 50,000 others, swimming in incessant circles like crazed zoo animals.

Whatever the species, these captive animals exhibit repetitive behaviour, pointlessly doing things over and over out of boredom and frustration.

Nowhere is our tendency to treat farmed animals as machines more clearly seen than in our use of genetic selection to fine-tune animals for ever-faster growth rates and higher yields. This leads to painful welfare problems, including lameness and mastitis in dairy cows, increased mortality, leg disorders and heart failure, chronic hunger in broiler breeders, and bone fractures in egg-laying hens.

To all intents and purposes, factory-farmed animals are not living; they are “existing” from the moment they are born.

However, it does not have to be this way.

Animal welfare science increasingly recognizes that good welfare for farmed animals means they have an opportunity to enjoy their lives. A “good life” means that all their behavioral, physical, environmental, and mental needs must be met.

The Five Domains model of animal welfare, developed by Professor David Mellor and Dr. Cam Reid, provides a comprehensive framework for assessing animal welfare. It focuses on four physical domains: nutrition, environment, health, and behavior, and one mental domain: the animal’s mental state. This model emphasizes that both positive and negative experiences impact an animal’s overall welfare.

It highlights the importance of providing animals with opportunities for positive experiences, such as social interactions and environmental enrichment, to ensure a good quality of life. The model has been widely adopted for evaluating welfare in various contexts, including research and agriculture [7-9].

What the Five Domains model demonstrates is that animal welfare, and thereby sustainable development, is best served by systemic changes away from industrial animal agriculture.

One Health promoting nature-positive, regenerative, or agroecological farming involves restoring animals to the land as rotational grazers or foragers where they can express their natural behaviours—running, flapping, and grazing—making for happier animals with better health too.

These farming methods maximize One Health in a range of different ways, not least through high animal welfare. They also cut reliance on chemical pesticides, fertilizers, and antibiotics, reducing costs to farmers and creating a varied landscape bursting with wildflowers that lure back pollinating insects such as bumblebees, as well as providing seeds and insects for birds and other wildlife.

The One Health approach underscores the necessity of interdisciplinary collaboration. Veterinarians, medical professionals, environmental scientists, and policymakers must work together to address the complex challenges at the intersection of human, animal, and environmental health. This collaborative effort is essential for developing and implementing effective strategies to improve animal welfare and, consequently, public health.

Education and awareness are also critical components of promoting animal welfare. Public education campaigns can inform communities about the importance of humane treatment of animals and the benefits of good animal welfare practices. Schools, universities, and community organizations can play a pivotal role in fostering a culture of respect and care for animals.

Legislation and policy play a vital role in ensuring animal welfare and sustainable development, not least through the transformation of agrifood systems. Governments must enact and enforce laws that protect animal welfare as part of creating future-fit food and farming practices that deliver One Health goals.

Philip Lymbery: conceptualization, methodology, investigation, validation, writing – original draft, writing – review and editing, visualization, resources, formal analysis, funding acquisition, data curation.

The author declares no conflicts of interest.