“If we are to tackle global human ill-health, we need to pay significant attention to One Health, taking a holistic approach to disease issues at the global level. Yet within One Health, the environment and wildlife health are too often the ‘poor relation’." ProfessorColin Galbraith, Chair of NatureScot, UK[1]

 In our post Covid world, zoonotic disease outbreaks are rarely far from the headlines. Rabies, Mpox and Ebola are well-established zoonotic diseases which have been sources of renewed concern in recent months, while the first ever case of Shamonda virus, which normally affects livestock, in a human has recently been reported in France[2].

Against this backdrop, it’s notable that animal health gets only a fraction of the attention, and associated investment, given to human health globally. Yet the interconnections between the health of wildlife, domestic animals and people are so profound that arguably all our futures depend on understanding how protecting wildlife health is key to human health security and wider planetary wellbeing.

This increasing understanding is reflected in the evolving concept of One Health, which is recognised by the UN as “an integrated, unifying approach that aims to sustainably balance and optimise the health of people, animals and ecosystems”[3]. It is an approach that “recognises the health of humans, domestic animals and wild animals, plants, and the wider environment (including ecosystems) are closely linked and inter-dependent”[4].

Looking at the world through such a comprehensive One Health lens, which gives parity to animal, human and ecosystem health, should mean it is increasingly evident that “conservation actions and health actions are highly intertwined”[5]. The drivers of biodiversity loss – habitat degradation and fragmentation, climate change, the illegal wildlife trade, pollution – which are often characterised as the key targets for conservation action, are also the drivers of cross-species health problems and emerging disease.

However, the reality still tends towards a narrower conception of One Health, where “most attention and investment…is currently directed towards known single health issues…of anthropocentric concern”[6]. Positive outcomes for human health still tend to be the central concern of policy and evaluation of success. Typically, that translates into a focus on zoonotic risk reduction, where disease-causing pathogens spillover from other animals to humans, especially in the aftermath of the Covid pandemic, and minimising the impact on animal production and agriculture, as illustrated by responses to the on-going avian flu (Highly Pathogenic AvianInfluenza – HPAI) crisis.

Despite widespread appreciationof the damage caused by human pandemics, there is still a tendency for public health policy to be more reactive – responding to impacts after they become evident– than preventative. However, there is now “growing evidence and acceptance that biodiversity protection is a cornerstone of pandemic prevention as well as instrumental to sustainable development and community health”[7]. Spreading that message and creating greater public awareness around the central importance of biodiversity protection can only be beneficial to the furthering of more holistic One Health approaches, and to establishing the concept that conservation actions are health actions, and vice versa.

Given global financial pressures, economic considerations are naturally of key importance. In 2022, the World Bank estimated that using One Health approaches could result in benefits of up to $37 billion globally[8].Yet, spending on animal health equates to just 0.4% of the global human health budget[9].This disparity leads to critical gaps in disease surveillance and investigation, particularly in resource-constrained LMICs where the wildlife-livestock-human interface is often more pronounced, increasing the likelihood of pathogen transfer, both from wildlife to livestock and humans, and vice versa. This imbalance “directly compromises global health security amidst growing connectivity, massive animal trade, and increasing agricultural intensification – all drivers for pathogen spillovers and contributors to broader planetary degradation”[10]. The enactment of genuine, cross-cutting One Health policies is hampered by the fact that “the veterinary sector, crucial for preventing, detecting and responding to health threats at their source, endures chronic underinvestment and is perceived to be of secondary importance” [11].

From a veterinary perspective, this is the reality we face, as committed advocates of wildlife health and capacity building in biodiverse regions. We urgently need to spread the word and educate the public about just how closely human health depends on wildlife health, ecosystem health and the conservation of biodiversity. It’s vital that we help local vets currently working in wildlife health to access the training they need not just to be able to dart and immobilise a rhino from a moving jeep and take the right kind of biomedical samples from the animal, but to understand the much bigger One Health picture – and how they can make a difference by addressing issues at the human-wildlife interface, and contribute to a range of wider inventions, from wildlife crime forensics, disease outbreak investigation and effective pathological examination, to ecological and population sampling and mapping, including methods for tracking and estimating distributions.

By ‘zooming in’ to look more closely at some of the drivers of disease in wildlife and how they are related to both biodiversity loss and human health, it’s possible to find concrete examples that potentially make it easier for people to identify with the fundamental principles underpinning a holistic, cross-cutting conception of One Health.

Habitat degradation through deforestation, fragmentation and intensive agriculture disrupts vital ecosystem services, like pollination and seed dispersal, while it brings humans, domestic animals and wildlife into ever closer contact, providing increasing opportunities for pathogen spillover between species. One example is the decimation of African lion populations by canine distemper virus, thought to have been originally transmitted by domestic dogs[12].It also increases the likelihood of human-wildlife conflict, where animals may destroy crops and property, or attack people. Responding to the related health challenges involves disease surveillance, alongside safe restraint and relocation of conflict animals, but also investigation into underlying health conditions which may be impacting conflict behaviour.

Among the effects of climate change are an increase in parasite resilience and burdens[13],and extension of the range and season of vector-borne diseases like blue tongue in wild and domestic ruminants, and of avian malaria in penguins, as well as one-off events like the mass die off of saiga antelope in Kazakhstan[14],equating to 60% of the global population, when increased temperature and humidity caused normally harmless Pasteurella bacteria to become suddenly and disastrously virulent, resulting in haemorrhagic septicaemia.

Over-exploitation and illegal trade of wildlife can reduce local genetic diversity and increase disease spillver risk, particularly when stress plays a significant role in greater virus shedding during capture and captivity.

Pollution is associated with a myriad of health-related impacts for humansa nd other animals. Sea otters, for example, have been known to die from toxoplasmosis as infected cat litter contaminates the ocean. Other instances range from ocean plastics causing intestinal blockages in sea turtles, and catastrophic poisoning of Asian vultures with diclofenac, to the impact of DDT pesticide on bird reproduction, and even light pollution disrupting their migratory pathways, causing collisions and disorientation. The decline of vultures in India in particular is strongly associated with a higher human death rate[15],as a result of increased rabies cases alongside other health impacts related to the loss to the ecosystem of the highly efficient scavenging behaviour of vultures ,and the resultant rise in feral dog numbers.

Armed conflict is another key area of concern, which is often responsible for unintended health consequences, like the unprecedented rise of rabies cases in Ukraine in recent years[16],as the feral dog and cat population grows and the interface with wildlife expands.

It's important to recognise that while Covid may have helped advance the One Health agenda in some respects, as public awareness of zoonotic disease potential has grown, it has also unfortunately increased the risk of persecution of species, like bats, which risk being seen as particular threats. Not only is there a great need for better public education on the vital ecosystem services provided by animals like bats, but it is important to make sure there is a renewed focus on animals more generally as victims of disease, rather than simply as potential sources. The fatal emerging fungal disease, white-nose syndrome, first recorded in New York state in 2006, has now killed millions of bats, sometimes with local population declines of over 90%. Fruit bats inAustralia are currently facing mass-starvation due to habitat loss and unusually dry weather, which have caused a critical shortage of nectar in flowering trees[17].

The UK Government published its National security assessment on global ecosystems earlier this year (January 2026), which states with“high confidence” that “every critical ecosystem is on a pathway to collapse" [18].But how can national and international policymakers respond effectively? There is an urgent need for concerted efforts to design policy-making frameworks where every decision involves consideration of what would be best for the health of people, animals and the environment, and where wildlife health is a stated conservation priority. There is potential for such an approach to grow out of the new WHO Pandemic Agreement, adopted in May 2025, as it evolves, as long as there is a concerted and fundamental shift to broaden health concerns from an emphasis on human public health to a broader concept of planetary health, focussed on building the resilience of all species. Approaches to new disease threats could then genuinely be transformed from being primarily reactive to being truly preventative. Furthermore, a move away from an “understandable but persistent focus on zoonoses” to a model “ensuring good protection of resilient ecosystems with fewer opportunities for spillover at anthropogenic or livestock interfaces” would foster a “more balanced and equitable One Health approach”[19].

A recent article in the Lancet (December2025) considered the World Organisation for Animal Health’s recent inaugural State of the World’s Animal Health report [20],which identifies some of the most pressing animal health challenges, including zoonoses, transboundary animal diseases, food security and biodiversity loss – recognising they are “all intertwined with human wellbeing”[21].

The authors of the Lancet paper are clear that, “the ability to address these hinges on a robust, equitably distributed and adequately resourced veterinary workforce worldwide”[22].They are equally clear that we are a long way from achieving that goal. Wildlife and environmental health are still often neglected in national and global health frameworks. More specifically, we know that “greater equity in One Health remains hindered byknowledge gaps in relation to the epidemiology and impact of many diseases in wildlife, compounded by inadequacies in wildlife health reporting”[23].

At a time when “governments, international forums, multilateral agreements and civil society are increasingly advocating for health, conservation and socio-economic concerns to be managed holistically across sectors and at multiple scales in a more coordinated and integrated manner”[24],it has never been more imperative to advance understanding of what conservation medicine can contribute and how veterinary expertise must be reflected at every level of policy making. Wildlife health has for too long been ‘inadequately understood and undervalued’ and treated as the ‘poor relation’ in the OneHealth arena. That needs to change.

Good health matters to all who share the planet. It is a unifying force that underlines the interconnectedness and interdependence of all living things. And that means that wildlife health must be an integral part of species conservation in order for solutions to be truly effective, leading not just to healthy wildlife but linking in turn to healthy people and a healthy planet, through the protection of biodiversity and reinstatement of resilient ecosystems.

“Conservation promotes health and health promotes conservation.”[25]

[1]  https://www.cms.int/sites/default/files/document/cms_cop14_inf.30.4.3_e_0.pdf,p5

[2] https://www.nature.com/articles/d41586-026-03416-1

[3] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp2

[4] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp2

[5] Dr Craig Stephen, MigratorySpecies & WildlifeHealth: A Pre-COP15 CMS Webinar: https://www.youtube.com/watch?v=gf9A3aT3QBw

[6] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp2

[7] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp3

[8] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp3

[9] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00281-5/fulltext

[10] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00281-5/fulltext

[11] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00281-5/fulltext

[12] Roelke-Parker, M., Munson, L.,Packer, C. et al. A caninedistemper virus epidemic in Serengeti lions (Panthera leo).Nature 379, 441–445 (1996)., p443 https://doi.org/10.1038/379441a0)

[13] For example: https://www.scops.org.uk/workspace/pdfs/farmers-weekly-article-on-haemonchus-october-2024.pdf

[14] https://www.ox.ac.uk/news/science-blog/scientists-uncover-why-200000-antelope-suddenly-died

[15] Frank, Eyal and Sudarshan, Anant,The Social Costs of Keystone Species Collapse: Evidence from the DeclineofVultures in India (January 5, 2023). University of Chicago, Becker FriedmanInstitute for Economics Working Paper No. 2022-165; p5 Available at SSRN: https://ssrn.com/abstract=4318579or http://dx.doi.org/10.2139/ssrn.4318579

[16] https://www.who.int/europe/news/item/05-12-2025-ukraine--rabies-is-now-an-increasing-threat-in-frontline-regions

[17] https://www.theguardian.com/environment/2026/oct/14/flying-foxes-in-nsw-and-victoria-face-mass-starvation-amid-food-shortages

[18] https://www.gov.uk/government/publications/nature-security-assessment-on-global-biodiversity-loss-ecosystem-collapse-and-national-security/national-security-assessment-on-global-ecosystems-accessible-version#:~:text=for%20the%20UK.-,(High%20confidence),(Moderate%20confidence)

[19] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp2

[20] https://www.woah.org/app/uploads/2025/05/the-state-of-the-worlds-animal-health-2025.pdf

[21] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00281-5/fulltext

[22] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00281-5/fulltext

[23] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp5

[24] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp3

[25] https://www.cms.int/publication/one-health-case-studies-resource-parties-convention-migratory-speciesp7

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