Human rights are a constantly evolving field of ethics and policy, as “natural rights” are increasingly recognised and respected in policy (Iriye et al., 2012). Within the United Nations (UN) system, human rights were first established on a policy footing by the UN Declaration of Human Rights in 1948 (UN, 2023a). Since then, the Declaration has inspired over 80 further international human rights declarations and treaties relevant to all or particular rights holders (UN, 2023b).

The UN has long recognised the human right to health. Article 25 of the Declaration states that “[e]veryone has the right to a standard of living adequate for the health and wellbeing of himself and of his family, including food, clothing, housing and medical care and necessary social services, and the right to security” (UN, 2023c). The International Covenant on Economic, Social and Cultural Rights has recognised the right to health as a human right (UN, 1966). Good health and wellbeing have also been recognised as part of sustainable development, which has a foundation in human rights (UN, 2015), most explicitly in Sustainable Development Goal 3: to ensure healthy lives and promote well-being for all at all ages (UN, 2015).

At the same time, the United Nations has a long record of marshalling environmental protection, from the 1972 UN Conference on the Human Environment in Stockholm, the establishment of the UN Environment Programme (UNEP) the same year; the World Charter for Nature of 1982 (General Assembly resolution 37/7); the Convention on Biological Diversity, with principles that recognise the “intrinsic value” of every form of life regardless of its worth to human beings (in preambular paragraph 1); and the Rio Declaration in 1992, which stipulates that human beings “are entitled to a healthy and productive life in harmony with nature”. The anthropocentric focus of some of these documents was already being described as “look[ing] somewhat dated” at the same time that the idea of humans having a right to a healthy environment was seen as fraught with difficult questions (Handl, 2012).

More recently, the human right to a clean, healthy and sustainable environment has been explicitly recognised in Article 11 of the San Salvador Protocol, implicitly within Article 26 of the American Convention and is now recognised by the United Nations Human Rights Council (UN, 2021) and the United Nations General Assembly (UN, 2022). A clean, healthy and sustainable environment is necessary for the full enjoyment of not only health, but a wide range of human rights, including the rights to life, food, water and sanitation and development (OHCHR, UNEP and UNDP, 2023).

This paper considers how this right includes a right to animal health and welfare. Its main argument is simple: it demonstrates that a healthy environment logically and evidentially needs to include healthy animals, including good welfare. The paper then considers potential nuances and implications of this conclusion.

While the main thrust of this paper seems apodictic, it is worth exploring some potential challenges to the view that healthy animals are a human right which may refine, if not refute, the underlying argument that the human right to a clean, healthy and sustainable environment includes a right to healthy animals. (In this, I will ignore wider challenges to rights theory, such as their universal applicability to all humans, which are beyond the scope of the paper.)

This paper has argued for the basic idea that humans’ right to a clean, healthy and sustainable environment includes a right to healthy animals within in, in line with the WHO concept of health, extended from humans to animals. The protection of humans, animals and their environments can be seen as parts of an interrelated and integrated responsibility.

The recognition of such a right should entail its respect and implementation. Part of ensuring the human right to a clean, healthy and sustainable environment is therefore ensuring animals’ basic health and welfare needs are met. We should protect the health and welfare of animals and the environment in itself and as part of human rights. This means that evidence of harms to human health or other rights, or of the potential for such harms, provides a significant and sufficient rationale for prioritising the protection of the environment and of the health of animals within it. It does not mean that it is not a necessary condition, in that the right to a healthy environment (healthy animals included) is a right in itself that is not limited to cases where there is evidence of such an impact.

Animal health and welfare can be seen as complementary aspects of a concern that includes animals’ physical, mental and environmental factors. World Health Organization (WHO)’s definition of (human) health above is complementary to the World Organisation for Animal Health’s Terrestrial Animal Health Code (WOAH, 2023b) which defines animal welfare as “the physical and mental state of an animal in relation to the conditions in which it lives” and the European Food Safety Authority’s characterisation of animal health as covering “animal diseases, as well as the interplay between animal welfare, human health, environmental protection, and food safety” (EFSA, 2023).

Substantively, animals would therefore need to be protected, where possible and proportionate, from excessive endemic and epidemic infections, malnutrition, stress and suffering. Domestic animals would need adequate veterinary care; nutrition; appropriate company, heterogeneity, and stocking densities; sufficient exposure to natural microbe level to build up their microflora and immunity; minimal severe or prolonged stress; and genetics that do not predispose them to health problems. It would also include ensuring animals are themselves in clean, and sustainable healthy environments because animals’ health can be affected by similar risk factors as humans’, including contaminants (Saegerman et al., 2006), pathogens and parasites (Marcogliese, 2008; Bordes and Morand, 2011), resource deprivations and climatic impacts on habitats, food, water and vector distribution (Lacetera, 2019; Domenici and Seebacher, 2020; Cheng et al., 2022), including risks for wildlife of infections from domestic animals (Kuiken and Cromie, 2022), as well as risks from humans’ infections, psychopathy, unhealthy behaviour and environmental impacts, and from other animals under human control (e.g. Tu et al., 2004). It would also require protection of animals’ parental, dependent, gregarious or mutualistic relationships with other animals or organisms (e.g. Herrera, 1985; Aslan et al., 2013). They will need protection from the health and wellbeing impacts of nature loss, pollution and climate change. Such protection for animals would also help protect the people who depend on them.

While the right discussed here does not define what level of animal health and welfare is required to respect human rights, it does give some indications. Firstly, it suggests that these should be in line with the definitions and standards of the WHO and WOAH, which include but go beyond the avoidance of infectious diseases in humans and animals. Secondly, it does not require that animals or environments to be completely sterile or abiotic, both because this is impossible and because this can have negative animal health impacts, for example on immune system or microbiome development. The aim should, rather, be in line with the WHO’s Constitution that envisages “the highest attainable standard of health as a fundamental right” (WHO, 1946). Thirdly, it would imply preventing risks to people and animals not directly involved in human–animal interactions, for example the risks to ecosystems and communities. Fourthly, it is not limited to cases where there is already evidence that poor animal treatment has caused human health compromises: the right to a clean, healthy and sustainable environment has now been recognised as a right in itself, which can therefore be breached even without – or before – evidence of clinical physical and mental health conditions in individual humans and, by extension, animals. Fifthly, while our policies might differ for different animals (e.g. wild versus domestic), the right would encompass all animals.

Even basic standards will require eliminating or significant modifying “unhealthy” human behaviours that create or exacerbate health risks for humans, animals and our environment, such as live animal trade and industrial animal farming (Jones et al., 2013; Hu et al., 2017; UNEP, 2022). As an illustration, animal welfare compromises caused by farming or trade practice can be associated with increased prevalence of pathogens such as Yersinia (Alpigiani et al., 2016), Campylobacter (Alpigiani et al., 2017), Leptospira (Kamaruzaman et al., 2022), Salmonella (Iannetti et al., 2020), Proteobacteria (Di Marcantonio et al., 2022), influenza (Henritzi et al., 2020) and coronaviruses (Alexakis et al., 2023; Kristianingrum et al., 2023; Liu et al., 2023; Rao et al., 2023).

While the necessary changes may apply primarily to the behaviour of keepers, consumers and corporations, it may also require changes on others whose behaviour affects those practices, such as through the consumption or overconsumption of products that damage animals’ health and environments (Willett et al., 2019). More positively, ensuring basic standards will require the improvement of animal healthcare infrastructures, both to ensure that nutritional, veterinary and other services are available and affordable for owners, and to ensure that these services are focused on ensuring animals and their environments are clean, healthy and sustainable. This means that protecting animal health and welfare also requires policy and structural change, with adequate consideration of animal health and welfare within agreements, policymaking and implementation processes.

Protecting animals is therefore relevant to procedural aspects of the right to a healthy environment (Knox, 2018), adapted for animals ( Box 1 ), and in line with the WHO’s principles that “[t]he extension to all peoples of the benefits of medical, psychological and related knowledge is essential to the fullest attainment of health,” and that “[i]nformed opinion and active co-operation on the part of the public are of the utmost importance in the improvement of the health of the people” (WHO, 2023). Policies should protect people who protect animals from discrimination, threats, harassment, intimidation and violence, in line with the Aarhus Convention and the Escazú Agreement. They should increase public information on animal welfare compromises and allow meaningful participation of the public and animal advocates in policymaking that affects animals and in practices to improve animal welfare. This might imply a need for product labelling and transparency about farming and trade practices. Such policies should be implemented and enforced effectively and protect and ensure animal health and welfare at least in line with agreed WOAH and civil society standards and without exclusions and exemptions for agriculture or commonly kept taxa. They should ensure robust and integrated prior assessments of policies’ environmental impacts, animal welfare impacts across all relevant domains (Mellor et al., 2020; Rae et al., 2023) and preparedness for human and animal health risks (Traore et al., 2023). Policies should also achieve equitable sharing of the harms from animal welfare compromises, so that harms to animal or environmental health limit profits, in line with the UN’s Guiding Principles on Business and Human Rights (UN, 2011).

Responsibilities to protect human rights may fall primarily on state governments, who “have a responsibility for the health of their peoples which can be fulfilled only by the provision of adequate health and social measures” (WHO, 2023). In addition, other organisations also play roles in protecting animal health and welfare, including international organisations such as the WOAH, Food and Agriculture Organisation of the UN, the UN Environment Programme, WHO, World Trade Organization, investors and development finance institutions. We might see this as part of a wider “Universal Declaration of Human Responsibilities” that includes protecting the health and welfare of animals and the environment, and recognises not only human rights but also our responsibilities.

A useful procedural comparison might be the situation in the European Union (EU), which recognises the need to pay full regard to animal welfare in Article 13 of the Lisbon Treaty of 2009 on the Functioning of the European Union (which also includes an explicit recognition that animals are sentient beings) and places a responsibility on the EU and its Member States to prevent maltreatment, pain and suffering. In this framework, animal welfare is not a competence at the EU level in its own right, but an objective of the EU policies, alongside principles such as non-discrimination, equal treatment and transparency. Animal welfare is also an integral part of the European Union’s Farm to Fork (F2F) strategy, which aims to make agriculture practices in Europe more sustainable through an integrated food policy that covers the full supply chain. The responsibility is at state level, with several countries including animals in their constitution, including Austria, Germany and Italy.

This implementation of the right to healthy animals might also promote increased collaboration between human, animal and environmental health sectors. For example, the links of planetary health, (human) public health and veterinary medicine may help understand how to apply methodologies of a given discipline to others, for example combining economics, behavioural ecology and ethology to consider how humans’ and animals’ resources could be met now and for future generations within genuinely sustainable solutions. The right to healthy animals would also seem compatible with approaches to a circular economy, by re-integrating animals into healthy natural relationships with their environments. Circular economy approaches must be based on respect for social foundations (Raworth, 2017), and these include “essential rights for humans and animals, such as the right to healthy and safe food, labour protections and farm animals expressing their species-specific behaviour [and] ensuring farm workers, fisherfolk and land managers – the frontliners of a circular bioeconomy – a prosperous livelihood” (Muscat et al., 2021).

This approach appears compatible with other approaches such as One Health that emphasise the link between animal welfare, human wellbeing, biodiversity and the environment (Zinsstag et al., 2023). The One Health High Level Expert Panel (OHHLEP) has described the foundational principles of One Health (OHHLEP, 2021; Adisasmito et al., 2022), which include “the inclusion and engagement of communities and marginalized voices”, “a harmonious balance between human–animal–environment interaction”, “acknowledging the importance of biodiversity, access to sufficient natural space and resources, and the intrinsic value of all living things within the ecosystem”, and “stewardship and the responsibility of humans to change behaviour and adopt sustainable solutions that recognize the importance of animal welfare and the integrity of the whole ecosystem, thus securing the wellbeing of current and future generations”. The OHHLEP have also highlighted the importance of preventing pandemics (OHHLEP, 2023), which includes a need to protect animal health and welfare (Fourpaws, 2023; WFA, 2023).

The One Health concept complements the development of the “One World, One Health” concept, in support of the 17 Sustainable Development Goals (SDGs), which call for all countries to build a global partnership and implement strategies that improve health and education, reduce inequality, protect the environment and support socially and environmentally sustainable economic growth. There is increasing recognition of the links of animal health and welfare with sustainable development (e.g. EFSA, 2023; Keeling et al., 2019) that illustrates a close mutually reinforcing relationship between animal welfare, human welfare (good health, reduced poverty and hunger) and biodiversity conservation.

The original contributions presented in the study are included in the article/supplementary material. Further inquiries can be directed to the corresponding author.

JY: Writing – original draft.