html xmlns=”http://www.w3.org/1999/xhtml”>
29 Animal subjects research Part II: Ethics of animal experimentation
The Case
Fifty hemophilic mice are anesthetized with an intraperitoneal injection of ketamine (which kills six mice), followed by blunt force trauma to a knee joint in half of the survivors. Post-trauma analgesics are administered only on day 0 and 1 following knee trauma. Two days later, and every 2–4 days thereafter, all mice are placed on a rotating rod and forced to ambulate until they fall off. Blunt trauma is administered in the test group weekly, and the process repeated. After 4 weeks, all mice are killed to examine their joints. The authors conclude that joint trauma and hemarthrosis leads to problems with ambulation and hemophilic synovitis –“consistent with clinical experience.”1
The editors of the journal in which this experiment appeared commented that the manuscript “proved challenging on review,” citing obligations of journal editors to assure that investigators minimize animal pain and suffering. One reviewer points out that progressive joint functional limitation is well known in human patients with hemophilia, particularly following trauma associated with hemarthrosis. He also raises concerns about animal suffering, pointing out that, although they were given analgesia for a brief period following acute trauma, the mice were forced thereafter to ambulate on traumatized joints without analgesia.2 Mice in the test group lost weight, limped, and fell off the rotating rod more quickly, all of which might be signs of pain and suffering that went untreated.
Nonhuman animals are used as subjects in research experiments, as test subjects for industries, and as objects for dissection and instruction in science classrooms – a subject of intense moral dispute. Most reviews addressing the ethics of animal research describe this debate as a war of wills between scientists and animal rights activists. Extremism on both fronts garners media attention. Leading scientists, and even some ethicists to insist that there is “no consensus” about the appropriate use of, and treatment of animals in testing, education, and research. But this is a distorted and misleading perspective. Specific moral frameworks regarding the use of animals by humans are evolving; nevertheless, there is moral, scientific, and public consensus about animals in research. It is likely that this consensus will evolve as our understanding of nonhuman animals deepens – their experiences, intelligence, and capacities for suffering, pain, and enjoyment. But it is imperative that every physician and researcher who uses animals in teaching, testing, and/or experimentation understands that they have explicit ethical obligations to their animal subjects.
Moral justifications of animal research
At its heart, the debate over the use of animals in research is centered on a single moral question: are humans morally justified in using animals in this way? Ethical arguments favoring animal experimentation generally fall into two categories: (1) humans have higher moral standing than animals and have a right to use animals in experiments that better human lives, and (2) the benefits of animal experimentation outweigh the harms, and that animal experimentation is sometimes the only way in which science can answer important questions necessary to human well-being.
The moral standing of humans versus animals
Western culture is heavily imbued with Judeo-Christian traditions, in which animal interests are subordinate to those of humans. Earth and its contents were bequeathed by a Creator to humankind to benefit humans. This view is still prominent among conservative Judeo-Christian leaders:
“The animal rights movement can best be understood by viewing it as an attempt to undo the opening chapters of the biblical Book of Genesis.” 3
In the last 50 years, detrimental effects of human populations on the environment have begun to threaten global repercussions. The views of conservative Judeo-Christian philosophers toward man’s relationship with the planet and nonhuman animals have begun to shift in response, but still describe the ethical obligations of humans in the utilitarian framework of serving the ultimate interests of mankind – i.e., we should take care of the environment and animals because, if we don’t, it will lead to depletion of resources and jeopardize the future of human existence.
Many twentieth-century religious scholars were challenged to reconcile new scientific theories and evidence (e.g., the theory of evolution and the fossil record supporting it) with mainstream theology. Pierre Teilhard de Chardin, a Jesuit priest and paleontologist, argued that, in parallel with biological evolution, humans are a part of a continuum in a “spiritual evolution” that also includes plants and animals.*4 Breaking down bright theological lines between animals and humans begs the question of whether our relationship with animals should really be viewed only through a utilitarian glass. Are we allowed to treat animals in ways that only promote human interests? Or do they have legitimate “interests” of their own? (For more discussion of ethical arguments regarding animal interests and rights, see Chapter 28.)
Are humans and nonhuman animals fundamentally different?
Up until the mid-to-late twentieth century, Western biologists operated under a “Cartesian” paradigm that attributed minimal, if any, intelligence to nonhuman species. Reasoning, emotions, and suffering were believed to be uniquely human attributes – animals were merely pre-programmed, instinct-driven robots that did not have moral standing.
“They eat without pleasure, cry without pain, grow without knowing it; they desire nothing, fear nothing, know nothing.”5
Current research demonstrates unequivocally that, far from being simple bundles of instinctual programming, the intellectual abilities of animals parallel that of humans in many startling ways. The manufacture and use of tools, long held to be a uniquely human ability, is now well described in nonprimate and even nonmammalian species.6 Animals demonstrate “culture,” in which uniquely individual and adaptive behaviors are passed within social groups by observation and mimicry, and not by instinct or genetic programming.7 The great apes appear to be capable of learning and using symbolic language, an important marker of abstract thinking.8 Meadow voles demonstrate “episodic recall,” believed to be an important marker of sentience.9 Whales and dolphins understand symbolic representations and have self-awareness,10 which has also been demonstrated in primates, elephants,11 and magpies.12
Why have animal researchers been slow to acknowledge these critical similarities with humans? Zoologist Frans de Waal proposes that “Our culture and dominant religion have tied human dignity and self-worth to our separation from nature and distinctness from other animals.” This cultural bias, he argues, keeps scientists from recognizing how similar humans and other animals really are, and thereby weakening arguments of human moral superiority.13
Bioethicist Bernard Rollin suggests that scientists now have an “ideology” of their own, in which they assert that science is “objective” and not burdened by moral values. “The bottom line,” he says, is the belief that “science might provide society with the facts relevant to making moral decisions, but it steers clear of any ethical debate.”14 But if it were true that there is no moral dimension to scientific endeavor, then there would be no need to argue that animal experimentation is permissible, nor that cruel experimentation on human subjects must be disallowed because it violates moral principles. Almost any experiment that simply produced new information would be allowed under such an ideology, without regard for treatment of any of its subjects, human or animal. The idea that medical research is immune from moral consideration has long been discredited, as exemplified in the Doctor’s Trial at Nuremberg after World War II.
Most bioethicists concede that many animals have at least some moral standing, although which animals and how much moral standing are unclear. Deliberately causing an animal to suffer due to pain, fear, starvation, illness, or poor conditions of care constitutes a moral harm to be prevented or mitigated, and considered carefully against the benefits such conditions might produce. Apart from any consideration of animal “rights,” many ethicists propose that cruelty to animals should still be discouraged, because it is likely that those who are cruel to animals will be cruel to humans as well.
Assessing the benefits of animal research
There is no doubt that animal experimentation has contributed to advances in anesthesia, cardiovascular and orthopedic surgery, treatment of such diseases as diabetes and hemophilia, vaccines, antimicrobial agents, cancer therapy, treatment protocols for trauma and shock, and many other areas. Yet is it simply not sensible to assert that medical science would have come to a complete halt without animal experimentation. As Harold Hewitt, himself an animal researcher, points out:
‘It underrates the ingenuity of researchers to assert that medical progress would have been seriously impeded had animal experiments been illegal, although a different strategy would have been required. It is the skill of the scientist to find a way around the intellectual, technical and ethical limits to investigation. No one complains, surely that we have been denied the benefit of potential advances by prohibiting experiments on unsuspecting patients, criminals or idiots.15
The contributions of animal experimentation to human medicine may also be greatly over-estimated. Critical analysis of the quality of animal experimentation leads to disturbing conclusions. A systematic review of animal experiments in fluid resuscitation, for example, found that many studies were fraught with poor design, were statistically underpowered, showed evidence of publication bias, and were seldom subjected to cross-species analysis or meta-analysis to determine if the results were even applicable to humans.16 Animal trials have been frequently conducted simultaneously with human trials, and were thus superfluous. They often set out to answer questions that had already been answered or could have been answered by a systematic review of existing studies.17 Historically, animal experimentation has, at times, been frankly misleading. It probably actually impeded such endeavors as developing the polio vaccine; understanding the role of asbestos exposure and lung disease; understanding the connections between tobacco smoke and lung cancer; and in developing other cancer treatments.18
An analysis of 76 animal studies cited in seven prominent scientific journals found that almost half were never subsequently tested in human trials. Of those that had been tested in humans, 18% were contradicted in the humans. Only 37% were eventually confirmed in human studies. Almost two-thirds of animal studies were not confirmed by testing in humans, and did not result in any human benefit.19 Another review of 221 experiments involving over 7000 animals found that results were in agreement with human studies in only 50% of cases. The authors found that basic methodological errors, such as lack of randomization and blinding, poor sample size, and publication bias probably contributed to poor concordance with human studies.20 In the words of physician R. Burns, “As physicians, researchers, and educators, we must take a long-overdue objective look at how and why we use animals in research and education. A great deal of animal-based research adds very little to our understanding of the diagnosis and treatment of our patients.”21
How many animals are used in research and testing laboratories? According to the United States Department of Agriculture (USDA), the use of “reportable” animals in research has declined steadily, from over 2 million animals in 1992, to just over 1 million in 2007.22 Because a 2002 amendment to the Animal Welfare Act (AWA) exempted laboratories from reporting research on birds, rats, and mice, USDA statistics only reflect the use of cats, dogs, hamsters, rabbits, guinea pigs, primates, and farm animals. Rats and mice are estimated to comprise approximately 95% of laboratory animals in research, and it is estimated that over 20 million animals are actually experimented on every year in the US.23 In 2007, about half of the reported experiments produced pain in the subjects, and almost 80 000 animals were subjected to pain without analgesia. An accurate number regarding how many “exempted” animals are subjected to untreated pain during research protocols is unavailable, but presumed to be in the millions.
According to the Home Office of Great Britain, approximately 3.7 million procedures were done on animals – including all vertebrates and one species of octopus – in research in the UK in 2008 that was deemed “likely to cause pain, suffering, distress, or lasting harm.” In only about 35% of procedures was some form of anesthesia or analgesia used.24
Related posts:
Informed consent and the pediatric patient
The use of ethics consultation regarding consent and refusal
Revising the Uniform Anatomical Gift Act – the role of physicians in shaping legislation
Conflicts of interest in research funding
Physician conscientious objection in anesthesiology practice
Opioid therapy in addicted patients: background and perspective from the US
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
