National Need and Priorities for Veterinarians in Biomedical Research (2004)

Having examined the adequacy of the comparative medicine veterinary workforce (Chapter 2), the authoring committee next turned its attention to projecting the future of this workforce. In order to develop an accurate workforce projection, the current workforce must be accurately defined and reasonable assumptions made about future demands on the workforce, as well as the entry of new workers into the field and their propensity to change fields, or retire, or die. This model was used to project the demographics of a comparable workforce—that of PhDs in biomedical and behavioral research (NRC, 2000). However, as documented in Chapter 2, data are not available to quantify the size of the current workforce accurately, though available evidence suggests that the current workforce is inadequate. For these reasons, the authoring committee was not able to create simulated projections of the future of the comparative medicine veterinary workforce. The committee was thus prompted to recommend that the AVMA utilize its current methodology for surveying their membership and recent graduates of veterinary medical schools and extend that methodology to (1) gather demographic information on the veterinary graduates of postgraduate training programs (both research and clinical), and (2) to include questions pertaining to curriculum and career choices in the survey instruments completed by graduates of veterinary medical and postgraduate training programs. This information would greatly assist veterinary medical colleges, postgraduate training programs, and NIH in understanding the effect of debt burden, starting salaries, dynamics of the job market, and curriculum on career choices.

In spite of the recognition that a formal projection of the workforce was not possible, the committee was still compelled to gather and analyze available data pertaining to the future demand for comparative medicine veterinarians and the supply of veterinarians entering the workforce and, recognizing the limitations of these data, to draw conclusions. In this case, the only available data on demand pertained to laboratory animal medicine veterinarians and veterinary pathologists. So, in addition, the committee identified several factors that could conceivably affect the demand for comparative medicine veterinarians in the near future. Fortunately, however, data pertaining to the supply of comparative medicine veterinarians (e.g., from NRSA training programs and specialty training programs) were more readily available and are discussed below.

Comparative medicine veterinarians can receive their postgraduate training in a clinical or research setting, through residencies or research training programs, respectively. Some comparative medicine veterinarians receive both clinical and research training.

Typically, an institution bears the costs associated with a residency program. From the mid-1960s to the mid-1990s, a small amount of clinical training was supported by the federal government. Clinical training for those individuals in a T32 research training program was supported by the T32 award (the National Cancer Institute and the National Institute on Aging also supported clinical fellowships in pathology). However, in the mid-1990s, NIH re-evaluated the use of the T32 funding mechanism and notified awardee institutions that the award was primarily for research training rather than clinical training. Since then, there has been no federal support of veterinary residency programs, and academic institutions have had to bear the costs of their residency programs, although several pharmaceutical companies have begun supporting training positions within academic institutions (Bennett, 1994).

The number of ACLAM-accredited laboratory animal medicine residency programs has not changed since 1995:32 active programs were known to exist in 1995 (Weigler et al., 1997), and there were 32 in 2002 (Table 3-1). Of the 32 currently active programs, nine programs did not

have an individual complete the program from 1996 to 2002. Four of those nine programs were newly established programs that had recently received ACLAM certification. Rockefeller University also had not trained any individuals from 1996 to 2002, but has recently reorganized its program into the Tri-institutional Program, with Weill Medical College at Cornell University and Memorial Sloan-Kettering Cancer Center, and has reapplied and received ACLAM certification.

In an effort to ascertain how many individuals had completed laboratory animal medicine residency programs, ACLAM surveyed recognized residency programs in early 2003 (ACLAM, 2003). This survey revealed that the number of individuals who completed residency training was 25% lower in 2002 than 1996 (Figure 3-1). This decrease in trainees paralleled a 2002 survey of residency programs (Colby, 2002), showing that 46% of the programs indicated a decrease in the number of qualified applicants apply-

FIGURE 3-1 Number of individuals that completed a residency in laboratory animal medicine at an ACLAM-recognized program.

Reflects all trainees that completed a residency program in laboratory animal medicine from a currently active ACLAM-accredited program. Also includes individuals from recently inactivated or reorganized ACLAM-accredited programs, State University of New York at Stony Brook, North Carolina State University, Yale University, and Rockefeller University. Source: American College of Laboratory Animal Medicine.

ing for residencies (8% indicated an increase in the number of applicants, and 46% indicated no change). However, it was not apparent from the survey whether this decrease in qualified applicants resulted in a decrease in the number of applicants accepted into a residency program. Several of the programs did indicate that lack of funding limited the number of residency positions at their institutions.

While there has been an overall decrease in the number of individuals completing residency training annually, this trend is not reflected in the number of individuals obtaining board certification (ACLAM membership) over a similar time period (1997-2002; this timeframe assumes that a graduate of a residency program would sit for board certification in the year immediately following completion of residency). The total numbers of individuals who completed residency programs (156 from 1996-2001) and obtained board certification (152 from 1997-2002) are similar, but when the annual fluctuations in ACLAM active membership are examined (Table 2-1 ), it is evident that a smaller number of individuals received board certification in 1997 through 1999 than one would predict from the number of individuals who completed an ACLAM residency program in the preceding year (see Table 3-1), and in 2002 a much larger number of individuals received board certification than would be predicted. These data suggest that some portion of graduates of ACLAM residency programs are not obtaining board certification within one year of completion of their residency. In addition, the decline seen in the number of individuals completing ACLAM residency programs may not translate into a decline in the number of individuals obtaining board certification for another three to five years. Another alternative is that some portion of those individuals completing ACLAM residency programs are not obtaining board certification, but rather an approximately equal number of individuals are fulfilling their board requirements through work experience, rather than completing a residency program. This possibility also warrants concern because it suggests that resources are being used to train individuals who are not obtaining their board certification.

To acquire veterinarians with experience in laboratory animal medicine for the uniformed services, it was necessary for the services to provide some of their members with the appropriate education, training, and experience. The US Air Force operated a residency program from 1961 to 1977, the US Army program has been in place informally since the 1950s, with a more structured program established in 1968, and the program at the Uniformed Services University of the Health Sciences (USUHS) was instituted during the 1990s (Kinnamon et al., 1999).

Most of the veterinarians that are trained in laboratory animal medicine through the uniformed services fulfill their 20-year obligation well before they reach retirement age. After their military service, these individuals are recruited into positions in the corporate and academic sectors. As of 1997, 32.7% of all ACLAM diplomates had received specialty training or experience that allowed them to sit for the ACLAM certification examination while on extended active duty in the uniformed services (Kinnamon et al., 1999). However, from 1998 through 2002, only 19.2% of new ACLAM diplomates had received their specialty training or experience through the uniformed services (ACLAM, 2003). This indicates that a larger percentage of the laboratory animal medicine veterinary workforce is being trained through ACLAM residency programs at academic and corporate institutions. As indicated in Figure 3-1, the overall number of graduates of ACLAM residency programs is also decreasing, which would indicate that the number of graduates of ACLAM residency programs with the uniformed services is declining at a faster rate than any decline in the number of graduates that may be occurring at ACLAM residency programs at academic and corporate institutions.

To estimate the current and future supply of veterinary pathologists, the American College of Veterinary Pathologists (ACVP), which administers the specialty-board certification for anatomic and clinical pathologists, surveyed both the employers and training programs of veterinary pathologists. While not every veterinary pathologist is engaged in biomedical research, this survey does provide some indication of the future of veterinary pathologists in biomedical research.

To perform this survey, the ACVP identified 278 employers of veterinary pathologists in Canada and the United States. A survey of this group (60.8% total response rate) indicated that the respondents employed 1,092 veterinary pathologists, which, extrapolated to include all identified employers, yields an estimated workforce in 2002 of 1,897 veterinary pathologists in Canada and the United States.* The survey also estimated 717 open positions for veterinary pathologists from 2002 to 2007.

This same survey also queried institutions that offered residencies in veterinary pathology. In 2002, there were 56 veterinary pathology residency programs with an estimated 381 veterinarians scheduled to complete a pathology residency between 2002 and 2007. Based on this survey, ACVP estimates that 336 positions will remain unfilled due to a lack of veterinary pathologists and that demand for veterinary pathologists will far outstrip the supply.

To identify underlying issues that might affect the supply of veterinarians being trained through residency programs, the ACVP survey also asked residency programs whether they had difficulty in recruiting qualified trainee candidates and whether there were limitations on the number of training positions available at their institutions. Of the residency programs, 77.7% indicated that it was somewhat or very difficult to recruit qualified trainees, and more than 90% indicated there were limitations on the number of training positions available at their institutions caused by lack of funding. When residency programs were asked to identify the barriers to recruiting qualified training candidates, a majority of the programs identified candidates’ concern with debt and low stipends as two barriers to recruitment. Additionally, more than one-third of programs indicated that candidates believe their residency programs are too long (the majority of programs were identified as three-year residencies, see Figure 3-2).

The AAVMC identifies 30 US veterinary medical colleges or schools and departments of veterinary science or comparative medicine that offer PhD programs in comparative medicine, biomedical sciences, pathology/ pathobiology, or laboratory animal medicine (Table 3-2). NIH supports some of those programs through NCRR-funded NRSA: Institutional Training Grants (T32s), which provide support for four to six trainees per institution (Table 3-2). At many of these institutions, the first year of clinical training is supported by the institution, which is a requirement for individuals to be supported by T32 funds. Many veterinarians will pursue PhDs during this training, although it is not required. In addition, some individuals will obtain board certification in laboratory animal medicine, having fulfilled the training prerequisites during their clinical training and T32-supported research training.

The T32 training grants are offered by NCRR’s Division of Comparative Medicine to provide three years of support for training veterinarians for research careers in biomedical fields related to comparative medicine or comparative pathology. The program description for the T32 training grants states that:

FIGURE 3-2 Type of veterinary pathology training program by specialty.

Reprinted from Veterinary Pathologist Survey: Final Report with permission of the American College of Veterinary Pathologists.

During 1994 to 2002, the median number of T32 training grants funded per year by NCRR’s Division of Comparative Medicine was 14 (range, 13-16). These T32-funded programs represent approximately half the research

training programs in the United States (Table 3-3). The success rate of these T32 grant applications is fairly high, with an average of 60% (range, 40-75%) of these grant applications receiving funding. Each T32-funded institution receives funding for four to six trainees per year; therefore, up to two individuals per institution would complete a 3-year training program per year (approximately 28 individuals per year would complete T32-funded training). From 1998 through 2002 (when the number of NIH competitive grants utilizing animals increased), the T32 award mechanism had the potential to produce a total of 142 veterinary scientists. However, because this estimate of 142 veterinary scientists assumes that each institution is

funded for and utilizes six trainee slots each year, it is an overestimate. In addition, not all T32-funded programs utilize all the training slots they receive funding for; some institutions currently have as few as two trainees supported on the T32 grant (F. Greider, personal communication).

While 142 veterinary scientists is a welcome addition to the comparative medicine veterinary workforce, this small number of individuals will not significantly increase the number of research programs headed by DVMs. Assuming that even half of the 142 potential T32-trained researchers achieve success as independent researchers who obtain RO1 funding, the percentage of RO1 grants utilizing animals that are led by DVM principal investigators will still be less than 7%.*

Since the attacks of September 11, 2001, and the dissemination of anthrax through the US Postal Service in the ensuing months, enormous resources—political, personnel, and fiscal—have been marshaled to prepare for bioterrorism attacks targeted directly at the American population or at its food supply. The National Institute of Allergy and Infectious Diseases alone will receive more than $1 billion in fiscal year 2003 for biodefense research (The Advisory Panel, 2002).

Considerable attention has been paid to bioterrorism agents, such as smallpox virus, that could be used to infect the American population directly, but there is increasing recognition that biologic and chemical agents can be spread through the agricultural system with potentially devastating

effects. For example, during World War I, German agents infected horses with bacteria that caused glanders (NRC, 2002). This disease is contracted by humans through direct contact with an infected animal and can then be transmitted from human to human through sexual or other direct contact. A more recent example occurred in Wisconsin in 1996, when someone intentionally contaminated animal feed with chlordane, an organochlorine pesticide that accumulates in the fat of an animal and can be harmful to people who ingest meat from a contaminated animal (NRC, 2002).

The CDC identified 18 biological agents most likely to be involved in a terrorist attack (Table 3-4). These biological agents were prioritized into two groups, category A and B diseases/agents, which pose a risk to national security because they are easily disseminated or transmitted and have high mortality or morbidity rates. Of the 18 identified biologic terrorism agents, 11 are agents of zoonotic diseases; that is, animals are the natural reservoir of the agents, which can be transmitted to humans. That not enough veterinarians are trained in public health or in the diagnosis and control of

zoonotic diseases reflects a lack of educational support and financial incentives for this aspect of veterinary science in the United States and the focus of most veterinarians on domesticated pets (The Advisory Panel, 2002). It has been noted that the emphasis of veterinary college curricula on clinical practice and research on diseases endemic in the United States causes a dearth of US-licensed veterinarians who have the expertise necessary to deal with agents of bioterrorism, which are often exotic animal diseases or diseases only infrequently encountered in the United States (The Advisory Panel, 2002).

The need for integrative and systems biologists has increased in the last half-decade. Translating the rapid advances made at the molecular and cellular level into advances in the prevention and treatment of diseases requires a cadre of scientists trained in comparative medicine and whole animal biology.

This need is reflected in the Senate Committee on Appropriations report on the 2002 appropriations bill for the Department of Health and Human Services. The Senate committee recommended increased support for research and training in systems and integrative biologic disciplines, given that there has been diminished support for research and training in systems and integrated biology during the last 2 decades in favor of cellular and molecular research. The Senate committee also noted that the erosion of support for systems and integrated biology threatened to lower the rate at which the discoveries made at the cellular and subcellular levels are translated into useful therapies (Harkin, 2001).

The need for specialists in comparative medicine was also highlighted by a National Research Council report (NRC, 1998a) stating that “there is a need for experts in comparative medicine who are well trained in laboratory animal medicine and in research methodology.” Comparative medicine veterinarians are particularly well suited for comparative medicine research in that their veterinary-school training is oriented to multiple species and they often receive both clinical and research postgraduate training. Postgraduate research-training programs that are funded by NRSA: Institutional Training Grants (T32) require applicants to have completed at least 1 year of postgraduate clinical training before being accepted as postdoctoral research fellows on T32 training grants.

Societal demands have brought about a heightened awareness of the need to accommodate for animal well-being and have stimulated the bio-

medical community to focus on and learn about animal pain and distress (NRC, 1992). The demands of the public have resulted in an evolution in the standards for laboratory animal care and use, which now require more hands-on involvement of qualified laboratory animal medicine professionals in the management of individual animals. Individual animals must be provided with pain control and distress relief, their aberrant behavior addressed, and their well-being ensured. As the handling and management of individual animals in a research environment become more refined, more clinically oriented veterinarians must be available to provide direction and oversight of animal health and well-being.

Another reason for the increased need for comparative medicine veterinarians is the growing regulatory requirements related to the use of animals in biomedical research. In fact, the rapid growth in demand for laboratory animal medicine veterinarians during the mid- to late 1980s (Figure 2-3) coincided with new federal legislation regulating the use of animals in research (Federal Register, 1991; Health Research Extension Act of 1985, 1985), though there was a decrease in the number of NIH competing grants using animals (Figure 2-1) (Weigler et al., 1997).

Most research institutions are now subject to the Animal Welfare Act (AWA) and Public Health Service (PHS) Policy, and many are accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC International). By the end of the 1990s, over-lapping and redundant policies and increased regulations originating from the AWA and PHS, as well as the growing importance of achieving voluntary accreditation by AAALAC International, created new documentation and reporting requirements that resulted in attending and staff veterinarians devoting much more time toward maintaining regulatory compliance for animal-based biomedical research (NIH, 1999).

Responsibility for directing and managing an institution’s animal care and use program generally falls to the attending veterinarian, who must have training or experience in laboratory animal science and medicine (NRC, 1996, p. 8), accompanied by responsibility for the institution’s PHS Policy Assurance, fulfillment of USDA reporting requirements, and retention of AAALAC International accreditation.

Both the AWA and the Guide for the Care and Use of Laboratory Animals (NRC, 1996) require (1) that every institutional animal care and use committee (IACUC) have at least one doctor of veterinary medicine who has training or experience in laboratory animal science and medicine and has direct or delegated program responsibility for activities involving animals housed in the research facility (9 CFR 2.31(b)(3)(i); NRC, 1996);

(2) that medical care for animals be available and be provided as necessary by a qualified veterinarian (9 CFR 2.31 (d)(1)(vii); NRC, 1996); and (3)that procedures that may cause more than momentary pain or distress be planned in consultation with the attending veterinarian (9 CFR 2.31 (d)(1)(iv)(B); NRC, 1996).

Given the mandated requirements, it is common for an attending veterinarian to be an IACUC member, to direct an animal care and use program, to consult with researchers on the development of protocols, to oversee the daily observations of animals, and to provide veterinary medical care as needed. All that effort leaves little time to direct independent research projects or to collaborate with researchers on issues outside basic animal care and use. Those realities have contributed to the division of laboratory animal specialists into those who focus on clinical, regulatory, and administrative matters and those who focus predominantly on academic activities and research.

The risks of infectious disease transmission and the ensuing adverse consequences in rodent colonies are increasing. The exchange of animals and animal products between facilities has increased, not only within the United States but also between facilities in the United States and abroad, where stringent disease prevention measures may not be in place. The risk of infection is greater in genetically modified rodents, whose response to infection is often unpredictable. The increasing size of institutional rodent colonies and the use of high-density housing systems are also increasing the risk of infection and complicating the ability of veterinarians to detect infectious agents. Respondents to a survey published in 1998 (Jacoby and Lindsey, 1998) were asked to identify factors affecting the ability of their institution to monitor and control infectious disease. The most commonly cited problem was inadequate financing, which resulted in an inability to attract and retain qualified veterinary personnel (Jacoby and Lindsey, 1998). Monitoring and controlling infectious disease require a team effort of veterinarians (and technicians) who specialize in medicine, pathology, and microbiology.

Infectious diseases of laboratory animals, particularly rodents, continue to affect biomedical research adversely. Laboratory rodents are susceptible to more than 50 infectious agents (Jacoby and Lindsey, 1998), and these can cause overt disease or subclinical infections, both of which affect the validity and reproducibility of research data (Rehg and Toth, 1998). An example is parvovirus, which is spread through contact with infected animals, equipment, and fomites. There are several strains of mouse and rat parvoviruses, and parvovirus-infected animals frequently manifest no patho-

logic changes, but infection with some strains can cause changes in the immune response and initiate autoimmunity (Smith, 2000). A national survey of rodent facilities at the country’s leading biomedical research centers found that 27 to 40% of mouse colonies and 28 to 32% of rat colonies had parvovirus infections (Jacoby and Lindsey, 1998). Pinworms and mouse hepatitis virus are prevalent and may be found in up to 70% of rodent colonies (Jacoby and Lindsey, 1998). Emerging diseases caused by infectious agents, such as enterohepatic helicobacters, which cause chronic lower bowel inflammation in immunocompromised rodents and liver tumors in some inbred strains of mice, are being increasingly recognized (Fox and Lee, 1997).

Infectious disease outbreaks are caused not only by the introduction of an infected animal into a facility but also by the use of infected tissues and reagents. An outbreak of mousepox in a colony at Cornell University in 1999 was caused by the use of mouse serum contaminated with ectromelia virus, the causative agent of mousepox (Lipman et al., 1999).

During the last 20 years, molecular and cellular scientists have made remarkable contributions to our understanding of human physiology and pathology. The biomedical research enterprise is on the cusp of a new era, that of translational research, which attempts to translate the gains of molecular and cellular biology into better prevention, diagnosis, and treatment of human and animal diseases. This type of research relies heavily on animal models, and all indications are that continued advances in genomics and proteomics will increase the use of animals, particularly rodents (Cassell and McCauley, 1996).

The development and use of transgenic animals—particularly rodents—has rapidly increased over the last 5 years. The publication of the human genome and the mouse genome has created a strong emphasis in biomedical research on functional genomics (NRC, 1998a). In light of the potential for 150,000 distinct mouse genotypes and thousands more phenotypes, it has been estimated that 60 million animals may be needed for mouse genomics research alone (Knight and Abbott, 2002). Many transgenic strains require intensive health monitoring, sophisticated husbandry, and incremental health care (Cork et al., 1997). High-quality care for the projected increase in the research rodent population would strain the current pool of laboratory animal medicine specialty-trained veterinarians.

An increase in the research rodent population not only would cause a strain on the pool of laboratory animal medicine veterinarians providing medical care for the rodent population, but also would require laboratory animal medicine veterinarians to train the many scientists who have little or

no background in animal research and are developing genetically engineered mice, not widely developed until the last 5 years. The scientists often require training by veterinary staff to carry out experimental procedures and comply with regulations (Cork et al., 1997). It is also conceivable that as the genomes of other laboratory animal species are decoded, the demand for laboratory animal medicine veterinarians with specialized knowledge of dogs, cats, rhesus macaques, and other common laboratory animal species will increase.

Comparative medicine veterinarians are integral to the successful development and assessment of transgenic animals. They have the comprehensive knowledge of disease processes and human and rodent diseases that is necessary to develop animal models or to consult with scientists who are developing animal models (Gaertner et al., 1998). Comparative medicine veterinarians with advanced training in pathology, neurology, cardio-pulmonary physiology, and animal behavior are essential to the successful development of transgenic animals.