Conservation medicine: how are animal health interventions used in the field to support threatened species?

Veterinary treatment for exotic pets and companion species, while not a new discipline, is a growing and developing branch of veterinary medicine and science. New advances in available drugs, treatment options and surgical interventions mean that we know more and more about the pathologies of “non-traditional” species, such as reptile, amphibian, fish and invertebrate pets. Much of this veterinary knowledge has stemmed from advances in the field of captive wild animal (“zoo animal”) veterinary surgery, with the knowledge being transferred from zoo vets to those working with privately owned exotic species. However, this same knowledge is now helping free-living animals as the burgeoning field of conservation medicine, which seeks to provide medical, health and well-being interventions for individuals of conservation concern species living in in situ (wild) populations.

What is conservation medicine and why is it important?

Conservation medicine is a stand-alone discipline that first appeared towards the end of the 1980s/at the start of the 1990s. It was brought about by the wider concern of vets and biologists who believed that the long-term health status of specialised animal species, or those living in fragmented populations or isolated habitats, was precarious and in need of dedicated care, monitoring and management programmes. Similarly, a growing realisation that human health and planetary health are intertwined saw the first efforts at understanding the impacts of disease on biodiversity. Conservation medicine provides a multifaceted, multidisciplinary approach to answering questions and solving problems relating to global biodiversity health challenges.

Conservation medicine provides a multifaceted, multidisciplinary approach to answering questions and solving problems relating to global biodiversity health challenges

Conservation and emerging infectious diseases

It is timely, perhaps, that this article is being written at the (fingers crossed) end of the SARS‑CoV‑2 pandemic – a global disease event linked to humankind’s lack of respect and regard for biodiversity and how we interact with it. Emerging infectious diseases (EIDs), of which COVID-19 is one of the most recent to hit human populations in such a devastating way, are one of the most important and significantly impactful threats to the health and sustainability of both humans and biodiversity itself in recent years.

Research into EID occurrences and their effects on wild animal populations shows that, without help or intervention, species extinction rates are markedly increased, and populations can be extirpated very quickly. The global amphibian conservation crisis, for example, involves several new pathogens, including fungal (chytridiomycosis) and viral pathogens (eg ranavirus that has been particularly prevalent in the UK common frog, Rana temporaria, population). EIDs are being increasingly, and more commonly, implicated in species decline and, when combined with other anthropogenic effects such as climatic change or the bushmeat trade which opens up new routes of transmission, are changing and evolving rapidly to cross into new areas and to new hosts. Conservation medicine is one piece of armour that can be used to understand EIDs and reduce their wider-scale impacts on species viability and persistence.

What makes up conservation medicine?

Conservation medicine is a truly interdisciplinary branch of veterinary medicine and science, incorporating elements of epidemiology, population biology, ecosystem and community ecology, conservation biology, animal husbandry and, of course, veterinary medicine and surgery. It also requires knowledge of project management, the practicalities and logistics of conducting fieldwork, developing networks of local expertise on the species in question, maintaining solid and fruitful relationships with all stakeholders involved in species conservation and care, and liaising with programme managers and those in charge of the national park, nature reserve or conservancy that the target species resides in.

It is a well-used adage, but a true one nevertheless, that conservation is ultimately all about people. When stripped down, conservation medicine is ultimately the interface between three overarching subjects (Figure 1): animal health, human health and ecosystem health. Table 1 provides examples of the reach and range of species and questions targeted by this approach.

Conservation medicine and a One Health approach

Anthropogenic causality is common when a disease is involved in species population decline. For example, research from 2018 has shown Batrachochytrium dendrobatidis, the strain of fungus that causes mass mortalities in frogs, to be present in all pet shop amphibians sampled, and that the global movement of exotic amphibians around the world has been responsible for the spread of this pathogen (O’Hanlon et al., 2018). Conservation medicine interventions have shown that the use of topical fungicides on infected wild amphibians can cure chytridiomycosis, but such direct treatment is not practicable on a global scale. Surveillance, monitoring, public education and ethical animal management practices are the best ways to remedy such wide-scale and devastating animal health issues.

The idea of a “One Health” or “Planetary Health” strategy is essential to reduce occurrences of emerging infectious diseases in the future

The idea of a “One Health” or “Planetary Health” strategy, to explain the interlinked lives of humans and wildlife and how the ecosystem services provided by nature are integral to the health and vitality of human and non-human animals, is essential to reduce occurrences of EIDs in the future. While conservation medicine shares many elements of traditional public health epidemiology, its main aim, to protect and improve animal health and ecosystems, in addition to human health, means it has a far-reaching and broader approach.