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The Flaws and Human Harms of Animal Experimentation


Nonhuman animal (“animal”) experimentation is typically defended by arguments that it is reliable, that animals provide sufficiently good models of human biology and diseases to yield relevant information, and that, consequently, its use provides major human health benefits. I demonstrate that a growing body of scientific literature critically assessing the validity of animal experimentation generally (and animal modeling specifically) raises important concerns about its reliability and predictive value for human outcomes and for understanding human physiology. The unreliability of animal experimentation across a wide range of areas undermines scientific arguments in favor of the practice. Additionally, I show how animal experimentation often significantly harms humans through misleading safety studies, potential abandonment of effective therapeutics, and direction of resources away from more effective testing methods. The resulting evidence suggests that the collective harms and costs to humans from animal experimentation outweigh potential benefits and that resources would be better invested in developing human-based testing methods.

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79. There is no direct analysis of the amount of money spent on animal testing versus alternatives across all categories; however, in 2008 the Chronicle of Higher Education reported that funding of research involving animals (under basic research) of the National Institute of Health (NIH) remained steady at about 42 percent since 1990. See Monastersky R. Protesters fail to slow animal research. Chronicle of Higher Education 2008:54. In 2012, NIH director Francis Collins noted that the NIH’s support for basic research has held steady at 54 percent of the agency’s budget for decades. The remainder of the NIH’s budget is heavily funded toward clinical research, suggesting that preclinical human-based testing methods are much less funded. See also Wadman M. NIH director grilled over translational research centre. Nature News Blog 2012 Mar 20. Available at (last accessed 5 Mar 2015). There is no data that suggests that the NIH’s funding of animal experimentation has decreased. A 2010 analysis estimates that at least 50 percent of the NIH’s extramural funding is directed into animal research; see Greek, R, Greek, J.Is the use of sentient animals in basic research justifiable? Philosophy, Ethics, and Humanities in Medicine 2010;5:14.

80. For a helpful discussion on animal pain, fear, and suffering, see DeGrazia, D. Taking Animals Seriously: Mental Lives and Moral Status. New York: Cambridge University Press; 1996:116–23.

81. See Akhtar A. Animals and Public Health: Why Treating Animals Better Is Critical to Human Welfare. Hampshire, UK: Palgrave Macmillan; 2012:chap. 5.

I am deeply indebted to David DeGrazia, Tom Beauchamp, and John Pippin for their careful review and helpful comments. The opinions expressed here are those of the author and do not represent the official position of the U.S. Food and Drug Administration or the U.S. government.

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