One-health approach bridges gap between science and human medicine
posted August 1, 2009
When reports surfaced earlier this year that some primates at the New Iberia Research Center in Louisiana had been mistreated, some people may have seen it as confirmation of their worst suspicions about laboratory animal research.
The Humane Society of the United States, which secretly videotaped alleged abuses, accused New Iberia staff of hundreds of Animal Welfare Act violations. A U.S. Department of Agriculture investigation of the facility ultimately resulted in just six citations for failing to comply with AWA standards. Meanwhile, the HSUS called on Congress to pass legislation ending invasive research on chimpanzees and retiring the approximately 500 federally owned chimpanzees to sanctuaries.
The controversy over New Iberia illustrates a key challenge for those working in laboratory animal medicine, namely, a perception that scientists systematically abuse their nonhuman subjects. The primate research community was deeply troubled by how they were portrayed by the media, and they sought to counter the negative image by explaining that the New Iberia incident is a rare exception in a field that is quite simply working to discover new drugs, vaccines, and medical technologies to save lives, both human and animal.
The public rarely considers the need for animals in biomedical research, says Dr. Christian R. Abee, director of the Michael E. Keeling Center in Bastrop, Texas, but when they do, they quickly understand why animals are a valuable resource. "We're really talking about the life and death of people," Dr. Abee said. "The new treatments being worked on can save millions of lives. Just as the discovery of penicillin saved untold numbers of lives, we're trying to discover the antibiotics for the future."
What the public may also not realize is, when a medical advance is first tested in animals, veterinarians are there, ensuring that the animals are humanely treated and that the therapy is shown to be safe enough to begin clinical trials in humans.
"We as veterinarians care about the animals, so we want to make certain they're used properly and that we do everything we can to minimize any discomfort these animals have. But we also recognize that it's only through this research that we're going to make progress in treating diseases killing many millions of people every year."
—DR. CHRISTIAN R. ABEE,
DIRECTOR, MICHAEL E. KEELING CENTER, BASTROP, TEXAS
Veterinarians have sworn an oath to protect animal health and relieve suffering in their patients. Yet they are equally committed to promoting public health and advancing medical knowledge about animals as well as humans. The tension between these dual obligations is nowhere more profound than in the field of laboratory animal medicine.
"We as veterinarians care about the animals," Dr. Abee explained, "so we want to make certain they're used properly and that we do everything we can to minimize any discomfort these animals have. But we also recognize that it's only through this research that we're going to make progress in treating diseases killing many millions of people every year."
Among the many animal species used in research, few are as highly valued physiologically as nonhuman primates. Because of their genetic, immunologic, reproductive, and neurologic similarities to humans, these animals are used as translational models involving a range of human illnesses, including cancer, HIV/AIDS, hepatitis, Parkinson's disease, Alzheimer's disease, and cardiovascular illnesses.
Advocates of primate research say medical breakthroughs such as the polio and hepatitis B vaccines would not have been possible or realized as soon as they were if these animals were not part of the investigations. "Primates are as close as you can get to the next step, which is clinical trials in humans," said Dr. Cheryl D. DiCarlo, assistant director of research resources at the Southwest National Primate Research Center in San Antonio, Texas.
Even with their many similarities to humans, a primate may not be ideal for a particular study, and it's up to the veterinarian supervising the study to decide, Dr. DiCarlo noted. "That's one of the things lab animal veterinarians do: they determine what species is the best model for a particular research project. Sometimes the mouse is the best model," she said.
Much of the research involving nonhuman primates is conducted at the eight National Primate Research Centers located throughout the country. Overseen by the National Institutes of Health's National Center for Research Resources, those facilities house an estimated 28,000 animals representing more than 20 species, including Old World primates like the chimpanzee, baboon, and rhesus macaque—the lion's share of primates used in research—and New World primates, including squirrel and owl monkeys. In addition, the centers operate breeding colonies to maintain the supply of several primate species for research.
Given the considerable costs associated with caring for a chimpanzee throughout its lifetime—as much as $500,000 over the span of 50 years—the NCRR in 1995 suspended financial support for the breeding of new chimpanzees. The center does provide ongoing monies for chimpanzees bred prior to the moratorium, and that includes retirement into a federally funded sanctuary system, such as Chimp Haven in Shreveport, La.
Primates are highly complex and social animals so, in addition to a team of veterinarians and veterinary technicians, each center employs a staff of behaviorists or trainers whose sole job is to provide environmental enrichment for the animals. It is understood in the research community that healthy and emotionally well-adjusted animals make the best test subjects.
Humans aren't the only ones who benefit from new medical therapies. According to Dr. Franziska B. Grieder, director of the NCRR Comparative Medicine Division, many advances in human medicine are now used to enhance and prolong animal life.
"We wouldn't have specific cancer treatments if they weren't first developed for human patients—or hip replacements or cardiac valves. We would never put those into dogs if they weren't developed for humans," Dr. Grieder said, and added that few biomedical companies would fund costly studies that benefited only animals.
Demand for primates fluctuates according to research needs at a given time. Research on HIV/AIDS, influenza, cancer treatments using monoclonal antibodies, and biodefense, for instance, are among some of the current hot topics. The NIH worries that new and emerging diseases will increase demand for research animals and there won't be enough veterinarians to look after the animals properly.
As with most career paths in veterinary medicine, with the exception of companion animal practice, a shortage exists of specially trained veterinarians who can meet the behavioral and physiologic needs of primates. The Association of Primate Veterinarians has 374 members, 33 of whom reside outside the United States, according to APV president, Dr. Thomas E. Nolan. Those numbers, Dr. Nolan said, encompass most if not all veterinarians working with primates.
"Primate medicine is a small fraternity, and (the fact) that jobs are going unfilled is pretty common knowledge," explained Dr. Bruce J. Bernacky, section chief of the rhesus monkey breeding colony and co-manager of the chimp colony at the Michael E. Keeling Center. "NIH can also see that more veterinarians are retiring than young people are coming into field."
To offset the shortage, the NCRR in 2007 began offering the R25 training grant at each of the primate centers to train veterinarians for careers in primate clinical medicine. Dr. Greg K. Wilkerson started his two-year residency at the Keeling Center in February. A 2001 graduate of the Center for Veterinary Health Sciences at Oklahoma State University, Dr. Wilkerson completed residencies in anatomic pathology and comparative medicine prior to striking out in this new direction.
"Primate medicine wasn't something I initially considered, just because I didn't have a lot of exposure to primates," Dr. Wilkerson said. "But once I did, I found it very fascinating. No two days are the same, and there are many opportunities for me."
The veterinarians interviewed for this article believe that, as champions of animal welfare, veterinarians are an essential component of biomedical research that uses animals. "We're sometimes perceived as torturing animals, but it's just the opposite. The veterinary staff is the animal advocate here," explained Dr. Kathleen M. Brasky, a clinical and research veterinarian at the Southwest National Primate Research Center.
"The animals are our top interest. (They're) not data from a project, whereas for an investigator, (the data) would be their primary interest. We're the animal advocate," Dr. Brasky explained.
The Animal Welfare Act requires veterinarians to provide pain relief to animals for any procedure that might be perceived to cause pain in a person. "I think lab animal veterinarians are much more attuned to pain and alleviating pain than human physicians," she said. "We err on the side of caution."
For more information about research primates and laboratory animal medicine, visit the Web sites of the Association of Primate Veterinarians (www.primatevets.org), American College of Laboratory Animal Medicine (www.aclam.org), and National Center for Research Resources (www.ncrr.nih.gov/). Additionally, the AVMA has several policies on animal research and appropriate care for the animals, including "AVMA Animal Welfare Principles," "Use of Animals in Research, Testing, and Education," and "Responsible Use of Animals for Human Purposes." These and other position statements are available on the AVMA Web site (www.avma.org) in the Reference section under "Policy."