Introduction

The WSAVA has adopted 'one health' as a major theme during its 50th anniversary year culminating in the 2010 Geneva congress. This special lecture provides background information on this topic and indicates how WSAVA might engage with the concept in the future.

One Health: Background

'One health' or 'one medicine' proposes the unification of the medical and veterinary professions with the establishment of collaborative ventures in clinical care, surveillance and control of cross-species disease, education, and research into disease pathogenesis, diagnosis, therapy and vaccination. The concept encompasses the human population, domestic animals and wildlife and the impact that environmental changes ('environmental health') such as global warming will have on these populations.

The concept is not a new one as a number of enlightened individuals historically practiced 'one health' and are regarded as the initiators of this field. One such individual was Sir John McFadyean (1853-1941) who was dually qualified as both a veterinary surgeon and medical physician and undertook research into major zoonotic diseases. Sir John also founded the Journal of Comparative Pathology (in 1888) that remains an important vehicle for dissemination of such research.¹ The 'rediscovery' of the concept is widely attributed to the veterinary epidemiologist Calvin W. Schwabe.² Academia, government and industry now well recognize the value of collaboration between human and veterinary physicians and scientists for the benefit of both man and animals in areas as diverse as experimental medical research, public health, food and environmental science, and bioterrorism. Numerous recent initiatives have occurred in this area. The theme of the 2007 AVMA Convention was 'one health' following from the liaison established in 2006 between the AVMA and the AMA.³ The keynote lecture at the 2008 Forum of the ACVIM was entitled 'One health, One Medicine: A Common Pathway for Veterinary and Human Medicine' and 'one health' was a recurrent theme at the 2008 International Conference on Emerging Infectious Diseases. In 2005 the BMA and the BVA co-published complementary volumes of the British Medical Journal and the Veterinary Record, highlighting the links between the professions.⁴ The UK Comparative Clinical Science Foundation has been established to promote and fund research into diseases affecting both man and animals and in 2009 this group hosted a symposium in London attended by over 100 UK medical and veterinary researchers.⁵ The Florida Health Department now produces an informative 'one health' newsletter. In Europe, major EU funding has been allocated to the LUPA project: a genomic study of canine diseases that may model equivalent human disorders and the FVE has announced a focus on 'one health'.

The most significant initiative has been the focus on 'one health' by a consortium of the OIE, WHO, FAO, UNICEF, UNSIC and the World Bank. This group produced a document on the co-ordination of medical and veterinary health policies that was adopted at a meeting of more than 100 country representatives in October 2008. Even more recently has been the announcement of the establishment of the 'One Health Commission' in the USA. This is a collaborative of eight professional organizations including the AVMA and AMA that emerged from the AVMA One Health Initiative Task Force.⁶

Are Small Companion Animals Important to 'One Medicine'?

The initiatives described above relate to efforts to improve human and animal health in the context of shared environment. Much of the focus will be on diseases and zoonotic diseases that occur in production animals and wildlife, improved environmental management and integrated laboratory research. There are however, numerous specific examples of major human diseases in which small companion animals play an integral role in transmission or by acting as reservoirs of infection. The two most immediate of these are rabies and leishmaniosis. Rabies remains a major disease of man that is often considered a neglected disease. Two thirds of the world's population live in a rabies endemic area and over 55,000 human deaths occur each year, mostly in Africa and Asia. The vaccination of dogs and control of stray dogs is crucial to rabies control. Recent initiatives in this area include⁷: 1) the third World Rabies Day supported by OIE, WHO and the US CDC and others, 2) European Veterinary Week with the theme of 'Animals + Humans = One Health', and 3) the award of $10 million by the Gates Foundation to the WHO Department of Control of Neglected Tropical Diseases for a study of rabies control focusing upon elimination of the disease in the dog.

Leishmaniosis is a similarly significant human disease endemic in many countries and for which the dog remains a reservoir of infection. Although not accorded the same significance as rabies, control of the disease in the canine population (by vaccination and stray dog control) is crucial. First generation Leishmania vaccines are now available in Brazil and appear effective in the field. The WHO also regards leishmaniosis as a neglected disease. The disease is present in 88 countries (72 of them are developing nations) and there are an estimated 2 million new human cases each year, with an estimated 12 million people currently infected.

Although these provide two clear examples of small companion animal diseases of global significance, the close relationship between pet animals and humans creates potential for disease transmission. Many emerging infectious diseases might potentially cross species barriers into dogs and cats and these animals may become a focus for disease control. An example for the potential of this scenario was the susceptibility of cats to infection with the recent avian influenza strain (highly pathogenic H5N1).⁸ Companion animal veterinarians must be vigilant in disease surveillance in these species.

In developed nations a further example of disease that has attracted much focus is methicillin resistant Staphylococcus aureus (MRSA) infection and the realization that these resistant organisms may infect companion animals (generally considered a transmission from man to animal).

Apart from these examples of direct interaction between human and small companion animal health, another major aspect of 'one health' is the integration of research efforts. It is widely recognized that the study of spontaneously arising canine and feline diseases holds great potential for understanding the human counterparts. Dogs and cats develop a wide range of infectious, neoplastic, inflammatory and immune-mediated diseases that are close mimics of disorders of man. The availability of the canine genome has allowed rapid progress to be made in recent years in such research.

What Role Could WSAVA Play in 'One Health'?

WSAVA is a unique organization that is a point of contact for over 70 national small animal veterinary associations. The fundamental remit of the organization is in scientific education which it achieves through an annual congress and by taking a programme of education into developing nations. The delivery of such education can already be regarded as a major contribution to 'one health' as practitioners in developing nations are at the forefront of existing and emerging infectious diseases that cross species barriers.

WSAVA is therefore uniquely poised to be able to rapidly contact and co-ordinate the efforts of the global small animal veterinary community, particularly those practitioners working in developing nations. For example, many of the WSAVA member nations are countries in which rabies and leishmaniosis are endemic diseases. The single most important role that WSAVA might play in the arena of 'one health' would be to establish a strong and effective global communications network. This might serve as an effective means of rapidly disseminating scientific information (for example in the case of a global disease pandemic involving companion animals), or initiating new disease control programmes, and could be of great benefit to organizations such as OIE. Given major funding, it would be feasible for WSAVA to co-ordinate global small companion animal infectious disease surveillance through sentinel practices in member nations contributing data to a central database.

A second activity of increasing importance for WSAVA has been in coordinating scientific progress through its standardization groups. The diseases that are the current subject of these activities involve the liver, gastrointestinal tract and kidney and in all of these areas there are canine and feline disorders that provide excellent spontaneously arising models of human disease. Whilst WSAVA supports only clinical (rather than experimental) research, there is enormous scope for greater integration of human and veterinary clinical research. As a direct example of this, the WSAVA Liver Standardization Group included amongst its membership a human hepatologist. The WSAVA is currently establishing a Foundation which will allow development of such shared scientific knowledge.

How is WSAVA Engaging with 'One Health'?

The WSAVA recognizes the significance of 'one health' and actively supports all of the current initiatives that are in play. The association believes that it has a potential role as global coordinator for small companion animal veterinarians to expand and promote their role in the 'one health' concept. At the 2010 Geneva congress, this focus has been promoted through this special lecture and by highlighting a series of 'one health' themed lectures throughout the programme. At the time of writing (January 2010) it is hoped that a major new initiative for WSAVA might be announced at this congress.

References

1.  Day MJ. J Comp Pathol 2008; 139: 151.

2.  Cardiff RD, et al. Lab Invest 2008 88: 18.

3.  Enserink M. Science 2007; 316: 1553.

4.  Alder M, Easton G. Vet Rec 2005; 157: 669.

5.  Anon Vet Rec 2009; 165: 159.

6.  King LJ, et al. JAVMA 2008; 233: 259.

7.  Alder M. Vet Rec 2009; 165: 329.

8.  Marschall J, Hartmann K. J Feline Med Surg 2009; 10: 359.