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ILAR Journal Vol 46(1)

Veterinary Medicine in the 21st Century: The Challenge of Biosecurity

Alan M. Kelly

Alan M. Kelly, Bv.Sc., Ph.D., MRCVS, is the Gilbert S. Kahn Dean of Veterinary Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.

Abstract

The veterinary profession is presently challenged with developing and maintaining on-farm biosecurity protocols to protect the nation's food supply from acts of bioterrorism, from the growing threat of foreign animal diseases, and from multidrug resistance among pathogenic organisms. This challenge comes at a time when the supply of food animal veterinarians in the United States is progressively in decline, and raises the possibility that the profession is not adequately prepared to fulfill its responsibilities to the health and productivity of the US livestock and poultry populations. Causes of the decline in demand for veterinary services are discussed. They include consolidation of the food animal industries and a trend toward transferring performance of tasks traditionally carried out by veterinarians to the province of lay staff. This development potentially reduces veterinary surveillance of food animal populations. It also runs the risk of delay in recognizing and controlling serious health problems when they arise. Several remedies are proposed, including profound changes in the curriculum for educating food animal veterinarians to serve the consolidated but vulnerable livestock and poultry industries suitably. Also advocated is the initiation of training programs for herdsmen on the symptoms of foreign animal diseases, together with advice on when to call a veterinarian. Significant investment of federal or state resources will be required if these changes are to become reality.

Key Words: agroterrorism; biosecurity; education; food animal veterinarians; herdsmen; multidrug resistance

In the post-September 11, 2001, environment, the veterinary profession must confront the possibility that it may not be prepared adequately to fulfill its responsibility for the health and productivity of the nation's livestock and poultry populations. The ease with which an agent such as the foot and mouth disease virus can be introduced, with malicious intent, to infect livestock and wildlife focuses attention on the present and future supply of food animal veterinarians.

An outbreak of foot and mouth disease could have devastating consequences for our economy and way of life. In Britain, the introduction of a single virulent strain of the virus led to the destruction of 10 million cloven hoofed animals (Meat and Livestock Commission 2002), a 6-mo ban on the export of all livestock products, and a devastated tourism industry. A disaster of similar magnitude in the United States would translate as destruction of all the livestock populations in New York, Pennsylvania, Ohio, West Virginia, Virginia, Maryland, Delaware, and New Jersey (H. Aceto, University of Pennsylvania, personal communication, 2003), the ruination of the tourism industry in eight middle Atlantic states, and a similar loss in export markets.

A second concern is the increasing threat from new and re-emerging, mostly zoonotic, infectious diseases such as Lyme disease, monkey pox, severe acute respiratory syndrome, bovine spongiform encephalopathy, avian influenza, and West Nile fever (Brown and Abee 2005; Patterson and Carrion 2005). Their appearance in our animal and human populations is an inevitable consequence of demographic shifts in world populations, globalization, air travel, poverty, pollution, and climate change, ingredients that will be with us throughout the 21st century and beyond.

The nation's interrelated agriculture and food handling and distribution system is immensely complex and extremely vulnerable, and much more must be done to guarantee its security (Brown 2003; Moon et al. 2003). However, adequate government support seems to await further heightened pubic awareness and anxiety from perceived threats to the food supply and from dangerous zoonotic diseases such as bovine spongiform encephalopathy and avian influenza.

Yet, it seems obvious that the need for adequate biosecurity measures on our farms should not be allowed to wait until agroterrorism becomes a reality. Our food animal producers and veterinarians already have more than enough to contend with: Johne's disease and Cryptosporidium are endemic, Escherichia coli O157 H7 and Campylobacter contaminate our food supply, and multidrug resistance among pathogenic organisms is being recognized with increasing frequency. Multidrug-resistant (MDR¹) strains of Salmonella Newport enterica have swept through the dairy cattle population and are now a serious threat to the equine industry. MDR S. Newport, an organism confined to the United States to date, can be lethal. Its appearance is almost certainly related to the profligate use of antibiotics. Many apparently normal animals carry and shed the organism, which complicates its control. Numerous reports of human disease associated with MDR S. Newport (Waxman 2002) are characterized by diarrhea, pain, fever, and malaise. It is of special concern in young children and immunosuppressed individuals.

In the absence of effective antibiotics, the control of MDR pathogens depends on rigorous biosecurity measures--routine disinfection, foot baths, personal hygiene, change of shoes and clothing as farm workers and veterinarians move from one facility to another, and limited access to animal housing--the same protocols that apply in the control of accidentally or maliciously introduced pathogenic organisms. Because MDR pathogenic organisms are here to stay, veterinarians, livestock and poultry farmers, and personnel who service the equine industry must now adhere strictly and routinely to clearly worded biosecurity protocols. Because the costs of such measures are not trivial and do not increase product value or sales, ways must be found to compensate farmers for their higher overhead for production.

Producers in the largely integrated poultry and swine industries are well ahead of the much less integrated dairy industry in adopting appropriate biosecurity measures. The image of cows standing in 3 or 4 inches of muck remains all too common. Under such conditions, Salmonella, E. coli 0157H7, Cryptosporidium, and Johne's disease are spread rapidly by the fecal/oral route, posing a constant threat to animal and public health and to the environment.

The emergence of MDR pathogenic organisms and the threat of agroterrorism focus attention on a critical set of challenges to the veterinary profession in terms of its ability to meet the profession's traditional responsibilities to society. The problem has been growing for more than two decades, during which time US veterinary schools have produced large numbers of graduates entering companion animal practice, while the numbers of graduates entering food animal practice has continued to decline. As a result, significant portions of the livestock industry, especially the dairy industry, have only limited coverage (Fetrow et al. 2004). The causes for the decline parallel the trend toward the consolidation of farming operations into larger units, with greater emphasis on herd productive efficiency and less emphasis on the health of individual animals (i.e., large farms generally use fewer veterinary services per animal) (Getz 1997). Many procedures traditionally performed by veterinarians are now the province of lay staff, a trend that runs the grave risk of delay in recognizing serious infectious disease problems when they arise. This shift is well established in the poultry and swine industries and will continue to affect the dairy industry, in which it has been estimated that 20,000 dairy farms--nearly 30% of the total--will go out of business in the next 6 yr (Fetrow et al. 2004).

This situation presents a serious, urgent challenge, not only for the veterinary profession but also for the safety of the nation's food supply and for the livestock industry. It seems evident that the present model of food animal practice, based on the diagnosis and treatment of individual animals and on competent veterinary surveillance of the nation's livestock populations, is unlikely to survive without substantial state or federal subsidies. Surveillance by veterinarians is crucial for the early recognition and control of highly infectious diseases such as foot and mouth disease and avian influenza.

In view of these seemingly persistent trends, it may be necessary for the profession to educate herdsmen on how to be on the lookout for foreign animal diseases and on when to call a veterinarian (D. Galligan, University of Pennsylvania, personal communication, 2004). At the same time, the profession must devise new ways to serve the livestock industry. Indeed, increasing numbers of veterinarians are employed by large food producing corporations as part of a management team whose aim is to maximize profit. These veterinarians participate in decisions on whole farm operation, facilities design, feeding regimens, nutrient management protocols, and breeding programs (Getz 1997). Risk management, biosecurity, computerized production records, and immediate recognition of when things go wrong are crucial services that veterinarians bring to such operations.

In educating food animal practitioners to the relevant present and ever-changing needs of agriculture, schools of veterinary medicine must adjust their curricular offerings to supplement the traditional medical disciplines with electives in economics, decision science, risk analysis, nutrition and crop selection, nutrient management, reproductive efficiency, facilities design, and computer science. Fortunately, a number of schools already have such programs in place. However, with the threat of agroterrorism, foreign animal diseases, and MDR pathogens, food animal veterinarians require additional skills, including the ability to diagnose diseases of wildlife and the ability to access data and updates on animal disease outbreaks anywhere in the world. Some knowledge of forensics and how to handle an event that may involve a criminal act is desirable, as is knowledge of Geographic Information System mapping and the mathematical modeling of disease control. Regular participation in emergency preparedness exercises is also important.

If veterinary schools are to remain relevant to our food animal industries, they will be obliged to produce graduates who can meet the challenges discussed in this brief treatise. But to attract veterinary students to careers in food animal practice, and to ensure that an adequate supply of food animal veterinarians capable of protecting the integrity and safety of our food animal industries stay in practice, will require a significant investment of state and federal dollars.

¹Abbreviation used in this article: MDR, multidrug-resistant.

References

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Fetrow J, Cady R, Jones G. 2004. Dairy production medicine in the United States. Bovine Pract 38:113-120.

Getz M. 1997. Agriculture. In: Veterinary Medicine in Economic Transition. Ames: Iowa State University Press. p 107-125.

Meat and Livestock Commission. 2002. Foot and mouth disease. Promed Ahead, January 27, 2002.

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Waxman Rep H. 2002. Congressional Record, Letter from Ranking Minority Member, Committee on Government Reform, to The Honorable A. Veneman, Secretary, USDA, August 5, 2002.