One Health approach to use of veterinary pharmaceuticals
An article featuring Professor Richard Kock has been published in the journal Science. The article, 'One Health approach to use of veterinary pharmaceuticals', was co-authored by 17 other scientists and researchers.
Professor Kock has been involved with the diclofenac story as an international veterinarian working at times in South Asia, when the pharmaceutical was causing devastating impacts and through his responsibilities as co-chair of the Wildlife Health Specialist Group of the IUCN (International Union for the Conservation of Nature). He led discussions between conservationists and colleagues in the R&D Pharmaceutical Companies like Astra Zeneca and brought the challenging issues around diclofenac and pharmaceuticals in the environment, in general, to the attention of the World Conservation Congress in 2008 and continues to lead at the IUCN on this issue.
In the article, the authors express concern about various impacts of the current level of use of veterinary pharmaceuticals. These impacts include environmental contamination through the manufacturing of pharmaceuticals, the treatment of animals and disposal of carcasses, offal, faeces, urine and unused products.
Within the article it is stated that more than 6,000 tonnes of active substances were used in the production of veterinary pharmaceuticals for use on livestock in the EU in 2004 alone. Making the point that, in the context of a growing demand for meat globally, with a parallel increase in use of veterinary pharmaceuticals, the environmental impact is likely to increase.
Although individual environmental levels have to be measured in picograms, the diversity and proliferation of chemicals with similar chemical structures and actions are leading to cumulative effects, not measured in conventional ecotoxicology or regulatory monitoring. non-steroidal anti-inflammatories and oestrogenic substances are some of the more prominent of these and which are having direct, measurable, negative impacts on biological systems and species themselves.
Contamination by this activity impacts upon non-target animal species, including humans. As a result of the environmental impacts, the authors recommend that regulation is increased and emphasis is placed on the holistic effect of veterinary pharmaceuticals.
The authors emphasise the need for a 'One Health' approach in relation to veterinary pharmaceuticals. The One Health model recognises the connections between human and animal health and the environment. As well as human communities being dependent on animals for food and livelihoods, the majority of infectious diseases can spread between animals and humans. Therefore promoting ecosystem health along with animal health and welfare ultimately supports human health and well-being.
In relation to veterinary pharmaceuticals, there is a difficult balance. While certain pharmaceuticals can support the heath of recipient animals, they can ultimately have a devastating impact on non-target animals and the ecosystem. The article gives the example of vulture species decimated by the use of a drug used on livestock until that pharmaceutical was controlled in India, Pakistan, Bangladesh and Nepal and a suitable alternative drug used. Nevertheless, the same drug has recently been allowed to be used in Spain, which holds more than 95% of the European populations of vultures and other species of endangered birds of prey.
A threat to vultures has other ecosystem impacts, as they help control disease and pests and also recycle nutrients. The article cites an estimate that vultures in Spain remove more than 8,000 tonnes of livestock carcasses annually, which prevents the release of greenhouse gases and also saves approximately £1.2m of disposal costs. But no monetary figure can be put on species endangered by ecosystem contamination.
The authors suggest that there should be initiatives to educate the public about the environmental impacts of veterinary pharmaceuticals and retailers and restaurants could do more to source and promote products produced under sustainable conditions. They also suggest greater collaboration between veterinarians, farmers, pharmacologists, ecologists and animal scientists to develop a more holistic and sustainable approach to the development of and use of veterinary pharmaceuticals. For example, the toxicology of these chemicals needs to be tested on a wider range of species than currently required in R&D where the focus of use is on human or domestic animals only. In the case of diclofenac, its toxic effects were never tested in birds during its development.
Professor Kock is co-director of the RVC innovative One Health (Infectious Diseases) MSc and Diploma programme, delivered in conjunction with London School of Hygiene and Tropical Medicine, and Chair in Wildlife Health and Emerging Diseases.