Human encroachment on the habitats of wild animals and the dense living conditions of farmed animals increase spill-over risk of emerging infectious diseases from animals to humans (such as COVID-19). In this article, we defend two claims: First, we argue that in order to limit the risk of emerging infectious disease outbreaks in the future, a One Health approach is needed, which focuses on human, animal, and environmental health. Second, we claim that One Health should not solely be grounded in collaborations between veterinary, medical, and environmental scientists, but should also involve more dialogue with animal and environmental ethicists. Such an interdisciplinary approach would result in epidemiology-driven measures that are ethically legitimate.
The ongoing COVID-19 pandemic is negatively affecting the life, health, social, and financial situation of millions of people. It has led to public debates about numerous ethical issues, especially in the fields of medical ethics, public health ethics, and political philosophy. Examples of these issues include questions about triage in hospitals, weighing the socio-economic impact of the crisis against lives saved, and the justifications invoked by governments for restricting the movement and social contacts of the inhabitants of their countries.1 Less attention has been paid by ethicists to possible measures that could be taken to prevent other epidemics and pandemics in the decades to come.2
In this article, we focus on ethical aspects relevant for the prevention of emerging infectious diseases (EID) – i.e., diseases that emerge in previously unaffected regions, such as COVID-19. We defend two claims. First, we argue that there is need for a scientific paradigm shift when it comes to the prevention of EIDs of zoonotic origin. Zoonotic diseases are those infectious diseases that are transmitted from vertebrate animals to humans. In order to limit the risk of zoonotic EID events in the future, a comprehensive and holistic approach is needed. One Health is an example of such a holistic approach, as it takes seriously the interconnection between human, animal, and environmental health.
So far, there is no agreement in the literature on the definition of One Health. One Health can broadly be described as “any added value in terms of health of humans and animals, financial savings or environmental services achievable by the cooperation of human and veterinary medicine when compared to the two medicines working separately” (Zinsstag et al. 2015). More recently, the United Nations Environmental Programme (UNEP) characterized One Health as “the collaborative effort across multiple disciplines to attain optimal health for people, animals and the environment” (UNEP 2020, 39). The One Health Initiative, on the other hand, defines it as “a worldwide strategy for expanding interdisciplinary collaborations and communications in all aspects of health care for humans, animals and the environment” (
The second claim we defend in this article is that One Health should not be limited solely to collaborations between natural scientists, but should also involve dialogue with ethicists. Only in this way can we ensure that measures taken to prevent and to combat the spread of EIDs have been examined from an ethical point of view, which, in turn, will legitimize decision-making processes.
2 The Need for a One Health Approach
The main aims of researchers and politicians within the framework of the ongoing pandemic are to halt the further spread of COVID-19 with the help of epidemiological measures and to develop therapies and vaccines to combat the disease. Indeed, therapies and vaccines for COVID-19 will, in the short and medium term, significantly alleviate human suffering and have the potential to considerably improve the health of millions of people in the months and years to come. However, this exclusive focus on human health is insufficient in the long term, as it will not help us to prevent future epidemics. Most EIDs affecting humans have their origin in non-human animal (hereafter: animal) populations (Jones et al. 2008). According to estimates, about 2.5 billion cases of illness and millions of deaths occur every year as a result of zoonoses (Grace et al. 2012). It is likely that around 60% of EIDs are zoonotic (Jones et al. 2008; Salyer et al. 2017). Examples include the Severe Acute Respiratory Syndrome (SARS) outbreak from 2002 to 2004, in which the disease is thought to have been transmitted from civet cats to humans (Wang et al. 2006), the Middle East Respiratory Syndrome outbreak in 2012, in which a coronavirus was transmitted from dromedary camels to humans (Haagmans et al. 2014), and the Ebola outbreak in West Africa from 2014 to 2015, which originated from contact between humans and infectious bats (Holmes et al. 2016). The current COVID-19 pandemic also has its source in an animal reservoir, with bats being suspected of having infected other animals as intermediate hosts, which in turn infected humans (Cyranoski 2020; Di Wu et al. 2020; Li et al. 2020).
Interactions between animal and human populations that increase the risk of infectious disease transmission are manifold (Magouras et al. 2020). For instance, livestock and agricultural intensification, along with modern farming practices, are associated with an increased risk of zoonotic disease emergence and amplification (Jones et al. 2013). Agricultural expansion promotes encroachment into wildlife habitats, deforestation, and the replacement of natural vegetation. This, in turn, leads to ecosystem changes and brings both humans and farmed animals into closer proximity with wild animals. Various animal species, including humans, thus become interlinked, something that would never happen in a natural, untouched ecosystem. As a result of this proximity, spillovers from pathogens between species become more likely, particularly in situations where both farmed and wild animals are hosted in close proximity or are traded on the same markets (Fournié et al. 2013). In addition to EID risks, this situation also raises important ethical issues regarding the welfare of both livestock and wild animals.
One Health ought to become the means of choice for preventing zoonotic diseases, since it takes the interdependence of human, animal, and environmental health seriously. While One Health initiatives date back to the 1800s, they have only started to receive more attention in the last twenty years (Bresalier et al. 2015). The recently published report “Preventing the next pandemic: Zoonotic diseases and how to break the chain of transmission” of the United Nations Environment Programme is an example of a policy briefing that advocates for the importance of One Health with regards to zoonotic disease prevention (United Nations Environment Programme and International Livestock Research Institute 2020). Several studies, for example Mindekem et al. (2017), have demonstrated that the One Health approach can result in considerable economic savings. However, although One Health initiatives have had considerable success in the past, such as in the case of schistosomiasis prevention and rabies control (Rabinowitz & Conti 2014), human, animal, and environmental health – and, as a consequence, veterinary science, environmental science, and human medicine – are in practice still frequently considered to be disciplinary silos. In many cases, the manifold links between them continue to be ignored, and there is less collaboration than there could be between their practitioners, particularly in the Western world.
It is, however, still an open question as to why One Health initiatives should take animal and environmental health seriously (van Herten et al. 2019): do they matter for their own sake, or only instrumentally, insofar as they promote human health? Coghlan & Coghlan (2018) note:
Despite the name One Health, some proponents and some definitions (e.g., WHO 2017) effectively portray attention to and/or improvement of nonhuman health as merely (though vitally) an instrument to the sole moral goal of optimal public (i.e., human) health. Unlike those who believe that nonhuman health is worth promoting and respecting intrinsically, One Health “instrumentalists” or “pragmatists” tend to see One Health in strongly anthropocentric terms. Accordingly, hard ethical thinking about the impacts of human health actions/inactions on nonhumans – such as how morally to handle trade-offs between human and nonhuman health – is of peripheral interest or not required.
In other words, One Health runs the risk of taking animal and environmental health into account solely to the extent that they serve and improve human health. However, such an approach fails to consider the moral importance of individual sentient animals and their well-being, as well as the impact of environmental health on animals and their welfare. Therefore, the ethical backbone of the One Health approach should be discussed more prominently.
3 The Need for Ethical Considerations within One Health
Over the last decades, the well-being of individual animals has become an important topic of investigation in animal ethics, a sub-discipline of philosophy. During the last 50 years, the focus of animal ethics has predominantly been on the moral standing of domesticated and captive animals. Animal ethicists mostly agree amongst themselves that sentient animals have moral status and matter morally for their own sake (see, for example, Regan 2004; Singer 2009; Cochrane 2012; DeGrazia 2012). This implies that humans have direct duties of non-maleficence towards these animals. The unnecessary suffering and pain of these animals should be avoided whenever possible. Many animal ethicists defend the “principle of equal consideration,” which requires that similar interests count alike, regardless of whether their bearer is human or animal (DeGrazia 1993; Singer 2009). However, this principle is rarely respected in the case of livestock: since the end of World War Two, an intensification of farming practices has been observed – away from small-scale family farms toward large-scale facilities, which sometimes hold thousands of animals of the same species (Graham et al. 2008). As a result, farmed animals nowadays frequently live in packed conditions that result in stress and are detrimental to their health and welfare. This, in turn, increases the risk of the rapid dissemination of infectious diseases among them (Cutler et al. 2010; Espinosa, Tago & Treich 2020).
With regards to wild animals, animal ethicists commonly used to argue in favor of a non-intervention (“laissez-faire”) approach – that is, simply leaving them alone (Everett 2001). However, in recent years, the focus of animal ethics has shifted. Animal ethicists have increasingly started to consider the interests, health, and well-being of sentient wild animals. Some have claimed that if individual sentient animals and their well-being count for their own sake in agricultural settings and research laboratories, it is unclear why the same principle should not apply to sentient wild animals. After all, it does not matter for individual animals whether their well-being is thwarted by moral agents or natural causes (Nussbaum 2007; Cochrane 2013). Hence, some animal ethicists have recently argued that we should intervene in the wild in some circumstances, in order to enhance the well-being of wild animals (Sözmen 2013; Horta 2018). Measures that have been proposed in order to promote this objective include the vaccination or treatment of wildlife (Kirkwood & Sainsbury 1996), helping and assisting wild animals after natural catastrophes (Hadley 2006), and sometimes even the genetic modification of predators or a significant reduction in their numbers to protect prey animals (McMahan 2015).
However, animal ethicists often discuss these issues only amongst themselves, rarely focus on particular diseases, and seldom engage in dialogue with veterinary scientists or ecologists about the feasibility and impact of the proposed measures – and vice versa. EID and zoonosis represent an example of such a neglected interdisciplinary exchange between natural scientists and ethicists. This is regrettable, since many diseases, along with their natural source and the effects of control interventions, can result in significant suffering for individual animals, not to mention entire populations. In other words, it is not only in the interest of humans to avoid infection with coronaviruses or other agents, but also in the interest of animals.
Recent developments in animal ethics may potentially make valuable contributions to debates about zoonotic EID outside the field of philosophical ethics. For example, animal ethicists have developed theories about land use, property rights, and sovereign territorial rights for wild animals (Donaldson & Kymlicka 2011; Hadley 2015) which could prove useful in the context of One Health. Considerations about the distribution of land and other resources between humans and wild animals – as well as compensatory measures in the event that this distribution is disrespected – could minimize contact zones between human, livestock, and wild animals, and in turn reduce the risk of EID spill-over.
In addition, more dialogue with environmental and animal ethicists may help to identify which interventions in the wild are ethically legitimate and potentially more sustainable in the long term. One common way of dealing with infectious wild animals is to cull them, in order to reduce the risk of disease spill-over (Degeling et al. 2016). However, culling harms individual animals and may destabilize the ecosystem as a whole. Through interdisciplinary collaborations bearing on real-world cases, veterinary scientists, ecologists, and animal and environmental ethicists would be able to identify the underlying values of epidemiological practices and to assess whether they exclusively benefit human health or also take into account individual animals, their health, their well-being, and their environment. Such an assessment would help to determine which actions should be chosen for the sake of humans, animals, and nature. Human, animal, and environmental health could potentially benefit tremendously from such an interdisciplinary exchange.
Admittedly, our suggestion may seem overly optimistic. After all, animal ethicists and environmental ethicists have major disagreements when it comes to questions concerning intervention in nature, which entities to ascribe moral value to, and deciding whom to protect in cases of conflict. There are some convergences, but also many divergences between animal ethicists (who usually defend a pathocentrist view) and environmental ethicists (who commonly defend biocentrist or ecocentrist views) (Horta 2018; Palmer 2018; Faria & Paez 2019).
Even though ethicists often do not agree amongst themselves, there are still two reasons for involving them in One Health approaches and fostering interdisciplinary collaboration. First, as we have already argued, One Health approaches raise ethical issues in many cases. Recruiting trained experts in ethics will ensure that the underlying values of decisions and actions have been properly considered and that the interests and integrity of everyone involved – humans, animals, and the environment – are appropriately balanced and not ignored or overlooked. The involvement of ethicists will allow for decisions that are proportionate to what is at stake, ensuring that, for example, the crucial interests of animals are not sacrificed for the sake of trivial human interests. Second, the involvement of ethicists is a question of procedural justice and allows for fair and transparent decision-making processes. Involving animal and environmental ethicists in One Health decision-making will guarantee that the impact of decisions on animals and the environment are considered in a fair way and not brushed aside, thus legitimizing the decision-making process. It will also allow for potential alternatives to be examined and for all relevant aspects to be properly weighed up, ensuring that the most important interests trump less important ones. Admittedly, there may still be disagreement about the permissibility of a given option. However, the involvement of ethicists in the decision-making process will help to legitimize the process, as well as the final decision.
In this article, we have argued in favor of the involvement of ethicists in One Health approaches to the prevention of EIDs. However, the dialogue between natural scientists and ethicists does not necessarily need to stop there. In addition to debates about the prevention of EIDs, animal and environmental ethicists can also contribute to a further issue, namely the question of how humans should interact with infectious animals once an EID event has already emerged. Past EID outbreaks, including those caused by coronaviridae, have led to violence against infected animals. For example, during the 2002–2004 SARS outbreak, some officials ordered the killing of more than 10,000 civet cats (Ng 2003; Parry 2004). The methods employed included drowning them in disinfectant. Similar worries about mass killings have been raised during the ongoing COVID-19 pandemic (Cyranoski 2020). Such mass killings of animals are neither sustainable nor ethically justifiable and probably do more harm than good in the long term. By fostering dialogue between veterinary science, biomedicine, environmental science, animal ethics, and environmental ethics, governments can implement more proportionate, effective, and sustainable measures when it comes to interactions between humans and infectious animals. This will, in turn, reduce the risk of further transmissions of EIDs from animals to humans in the future.
We would like to thank Alexander Madsen and a reviewer of the Journal of Applied Animal Ethics Research for their useful comments on a previous version of this manuscript.
Bresalier M., Cassidy A. & Woods A. (2015). “One Health in history”. In J. Zinsstag, E. Schelling, D. Waltner-Toews, M. Whittaker & M. Tanner (Eds.), One Health. The Theory and Practice of Integrated Health Approaches (pp. 1–15. Wallingford: CABI.
Cochrane, A. (2012). Animal Rights Without Liberation. Applied Ethics and Human Obligations. New York: Columbia University Press.
Cochrane A. (2013). “Cosmozoopolis: the case against Group-Differentiated Animal Rights”. Law, Ethics and Philosophy, 1, 127–141.
Coghlan, S. & Coghlan, B. (2018). “One Health, bioethics, and nonhuman ethics”. The American Journal of Bioethics, 18 (11), 3–5.
Cutler, S.J., Fooks, A.R. & van der Poel, W.H.M. (2010). “Public health threat of new, reemerging, and neglected zoonoses in the industrialized world”. Emerging Infectious Diseases, 16 (1), 1–7.
Degeling, C., Lederman, Z. & Rock, M. (2016). “Culling and the common good: re-evaluating harms and benefits under the One Health paradigm”. Public Health Ethics, 9(3), 244–254.
DeGrazia, D. (1993). “Equal consideration and equal moral status”. The Southern Journal of Philosoph, 31 (1), 17–31.
Di Wu, Wu, T., Liu, Q. & Yang, Z. (2020). “The SARS-CoV-2 outbreak: What we know”. International Journal of Infectious Diseases, 94, 44–48.
Espinosa, R., Tago, D. & Treich, N. (2020). “Infectious diseases and meat production”. Environmental & Resource Economics, 76, 1019–1044.
Everett, J. (2001). “Environmental ethics, animal welfarism, and the problem of predation. A bambi lover’s respect for nature”. Ethics and the Environment, 6 (1), 42–67.
Faria, C. & Paez, E. (2019). “It’s Splitsville: why animal ethics and environmental ethics are incompatible”. American Behavioral Scientist, 63 (8), 1047–1060.
Fournié, G., Guitian, J., Desvaux, S., Cuong, V.C., Dung, D.H., Pfeiffer, D.U., Mangtani, P. & Ghani, A.C., (2013). Interventions for avian influenza A (H5N1) risk management in live bird market networks. Proceedings of the National Academy of Sciences of the United States of America, 110, 9177–9182.
- Search Google Scholar
- Export Citation
, ( , Fournié, G. , Guitian, J. , Desvaux, S. , Cuong, V.C. , Dung, D.H. , Pfeiffer, D.U. & Mangtani, P. Ghani, A.C. ). 2013 Interventions for avian influenza A (H5N1) risk management in live bird market networks. Proceedings of the National Academy of Sciences of the United States of America, 110, 9177– 9182. 10.1073/pnas.1220815110
Grace D., Mutua F., Ochungo P., Kruska R., Jones K., Brierley L., Lapar L., Said M., Herrero M., Phuc P.M., Thao N.B., Akuku I. & Ogutu F. (2012). Mapping of poverty and likely zoonoses hotspots. Zoonoses Project 4. Report to the UK Department for International Development. Nairobi, Kenya: ILRI.
Graham, J.P., Leibler, J.H., Price, L.B., Otte, J.M., Pfeiffer, D.U., Tiensin, T. & Silbergeld, E.K. (2008). The animal-human interface and infectious disease in industrial food animal production: rethinking biosecurity and biocontainment. Public health reports (Washington, DC: 1974) 123, 282–299.
- Search Google Scholar
- Export Citation
( , Graham, J.P. , Leibler, J.H. , Price, L.B. , Otte, J.M. , Pfeiffer, D.U. & Tiensin, T. Silbergeld, E.K. ). 2008 The animal-human interface and infectious disease in industrial food animal production: rethinking biosecurity and biocontainment. Public health reports (Washington, DC: 1974) 123, 282– 299.
Haagmans, B.L., Al Dhahiry, S.H.S., Reusken, C.B.E.M, Raj, V.S., Galiano, M., Myers, R., Godeke, G.-J., Jonges, M., Farag, E., Diab, A., Ghobashy, H., Alhajri, F., Al-Thani, M., Al-Marri, S.A., Al Romaihi, H.E., Al Khal, A., Bermingham, A., Osterhaus, A.D.M.E., AlHajri, M.M. & Koopmans, M.P.G. (2014). “Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation”. The Lancet Infectious Diseases, 14 (2), 140–145.
- Search Google Scholar
- Export Citation
( , Haagmans, B.L. , Al Dhahiry, S.H.S. , Reusken, C.B.E.M , Raj, V.S. , Galiano, M. , Myers, R. , Godeke, G.-J. , Jonges, M. , Farag, E. , Diab, A. , Ghobashy, H. , Alhajri, F. , Al-Thani, M. , Al-Marri, S.A. , Al Romaihi, H.E. , Al Khal, A. , Bermingham, A. , Osterhaus, A.D.M.E. & AlHajri, M.M. Koopmans, M.P.G. ). “ 2014 Middle East respiratory syndrome coronavirus in dromedary camels: an outbreak investigation”. The Lancet Infectious Diseases, 14( 2), 140– 145. 10.1016/S1473-3099(13)70690-X
Hadley, J. (2006). “The duty to aid nonhuman animals in dire need”. Journal of Applied Philosophy, 23 (4), 445–451.
Holmes, E.C., Dudas, G., Rambaut, A. & Andersen, K.G. (2016). “The evolution of Ebola virus: insights from the 2013–2016 epidemic”. Nature, 538 (7624), 193–200.
Horta, O. (2018). “Concern for wild animal suffering and environmental ethics: what are the limits of the disagreement?”. Les Ateliers de l’Éthique / the Ethics Forum, 13 (1), 85–100.
Jones, K.E., Patel, N.G., Levy, M.A., Storeygard, A., Balk, D., Gittleman, J.L. & Daszak, P. (2008). “Global trends in emerging infectious diseases”. Nature, 451 (7181), 990–993.
Jones B.A., Grace, D., Kock R, Alonso, S., Rushton, J., Said, M.J., McKeever D., Mutua, F., Young, J., Mcdermott, J. & Pfeiffer, D.U. (2013). Zoonosis emergence linked to agricultural intensification and environmental change. Proceedings of the National Academy of Sciences of the United States of America PNAS, 110 (21), 8399–8404.
- Search Google Scholar
- Export Citation
( , Jones B.A. , Grace, D. , Kock R , Alonso, S. , Rushton, J. , Said, M.J. , McKeever D. Mutua, F. , Young, J. & Mcdermott, J. Pfeiffer, D.U. ). 2013 Zoonosis emergence linked to agricultural intensification and environmental change. Proceedings of the National Academy of Sciences of the United States of America PNAS, 110( 21), 8399– 8404. 10.1073/pnas.1208059110
Kirkwood, J.K. & Sainsbury, A.W. (1996). “Ethics of interventions for the welfare of free-living wild animals”. Animal Welfare, 5 (3), 235–243.
Lei, R. & Qiu, R. (2020). “A strategy to prevent and control zoonoses?”. The Hastings Center Report, 50 (3), 73–74.
Li, C., Yang, Y. & Ren, L. (2020). “Genetic evolution analysis of 2019 novel coronavirus and coronavirus from other species”. Infection, Genetics and Evolution, 82, 104285.
Magouras, I., Brookes, V.J., Jori, F., Martin, A., Pfeiffer, D.U. & Dürr, S. (2020). “Emerging zoonotic diseases: should we rethink the animal-human interface?” Frontiers in Veterinary Science. doi:10.3389/fvets.2020.582743.
McCallum, H. & Hocking, B.A. (2005). “Reflecting on ethical and legal issues in wildlife disease”. Bioethics, 19 (4), 336–347.
McMahan, J. (2015). “The moral problem of predation”. In A. Chignell, T. Cuneo & M.C. Halteman (Eds.), Philosophy comes to dinner. Arguments about the ethics of eating (pp. 268–294). New York: Routledge.
Mindekem, R., Lechenne, M.S., Naissengar, K.S., Oussiguéré, A., Kebkiba, B., Moto, D.D., Alfaroukh, I.O., Ouedraogo, L.T., Salifou, S. & Zinsstag, J. (2017). “Cost description and comparative cost efficiency of post-exposure prophylaxis and canine mass vaccination against rabies in N’Djamena, Chad”. Frontiers in Veterinary Science, 4, 38.
- Search Google Scholar
- Export Citation
( , Mindekem, R. , Lechenne, M.S. , Naissengar, K.S. , Oussiguéré, A. , Kebkiba, B. , Moto, D.D. , Alfaroukh, I.O. , Ouedraogo, L.T. & Salifou, S. Zinsstag, J. ). “ 2017 Cost description and comparative cost efficiency of post-exposure prophylaxis and canine mass vaccination against rabies in N’Djamena, Chad”. Frontiers in Veterinary Science, 4, 38.
Ng, S.K.C. (2003). “Possible role of an animal vector in the SARS outbreak at Amoy Gardens”. The Lancet, 16 (362) (9383), 570–572.
Nussbaum, M.C. (2007): Frontiers of justice. Disability, nationality, species membership. Cambridge: The Belknap Press of Harvard University Press.
One Health Initiative (2021). Available at: https://onehealthinitiative.com/.
Palmer, C. (2018). “Conservation strategies in a changing climate – moving beyond an “animal liberation/environmental ethics” divide.” Les ateliers de l’éthique/The Ethics Forum, 13 (1), 17–42.
Rabinowitz, P.M. & Conti, L.A. (2014). “One Health successes and challenges” In A. Yamada, L.H. Kahn, B. Kaplan, T.P. Monath, J. Woodall & L. Conti (Eds.), Confronting emerging zoonoses (pp. 241–251). Tokyo: Springer Japan.
Salyer, S.J., Silver, R., Simone, K. & Barton Behravesh, C. (2017). “Prioritizing zoonoses for global health capacity building – themes from One Health zoonotic disease workshops in seven Countries, 2014–2016”. Emerging Infectious Diseases, 23 (13), 55–64.
- Search Google Scholar
- Export Citation
( , Salyer, S.J. , Silver, R. & Simone, K. Barton Behravesh, C. ). “ 2017 Prioritizing zoonoses for global health capacity building – themes from One Health zoonotic disease workshops in seven Countries, 2014–2016”. Emerging Infectious Diseases, 23( 13), 55– 64.
Sözmen, B.İ. (2013). “Harm in the wild: facing non-human suffering in nature”. Ethical Theory and Moral Practice, 16 (5), 1075–1088.
United Nations Environment Programme and International Livestock Research Institute (2020). Preventing the next pandemic: zoonotic diseases and how to break the chain of transmission. Nairobi, Kenya.
van Herten, J., Bovenkerk, B. & Verweij, M. (2019). “One Health as a moral dilemma: towards a socially responsible zoonotic disease control”. Zoonoses and Public Health, 66 (1), 26–34.
Wang, L, Shi, Z., Zhang, S., Field, H., Daszak, P. & Eaton, B.T. (2006). “Review of bats and SARS”. Emerging Infectious Diseases, 12 (12), 1834–1840.
Wu D., Wu, T., Liu, Q. & Yang, Z. (2020). “The SARS-CoV-2 outbreak: what we know”. International Journal of Infectious Diseases, 94, 44–48.
Zinsstag J., Waltner-Toews D. & Tanner M. (2015), “Theoretical issues of One Health”. In J. Zinsstag, E. Schelling, D. Waltner-Toews, M. Whittaker & M. Tanner (Eds.), One Health. The Theory and Practice of Integrated Health Approaches (pp. 16–25, at 18). Wallingford: CABI.
- Search Google Scholar
- Export Citation
( & Zinsstag J., Waltner-Toews D. Tanner M. ), “ 2015 Theoretical issues of One Health”. In (Eds.), One Health. The Theory and Practice of Integrated Health Approaches (pp. , J. Zinsstag , E. Schelling , D. Waltner-Toews & M. Whittaker M. Tanner 16– 25, at 18). Wallingford: CABI.