Animals in Science / Research

Limitations and Dangers

Relying on animal research and testing to protect and improve human health is not only unsafe, but also expensive, time-consuming, and unreliable. Problems of extrapolation—applying information from animal research to humans—are inevitable when researchers use animal models to study human diseases. Species differences in anatomy, organ structure and function, toxin metabolism, chemical and drug absorption, and mechanisms of DNA repair—among myriad other differences between humans and other species—can give us inadequate or erroneous information when we attempt to apply animal data to human diseases and drug responses. For example, penicillin is toxic to guinea pigs, aspirin is poisonous to cats, and the recalled diet drug phen-fen caused no heart damage in animals, while it did in humans. And despite millions of animals used and billions of taxpayer dollars spent on cancer research, roughly 95 percent of cancer drugs that enter human clinical testing fail while our incidences of cancer have continued to rise. Stated by Dr. Richard Klausner, former Director of the National Cancer Institute, “We have cured cancer in mice for decades—and it simply didn’t work in humans.”[1] Even chimpanzees, our closest genetic relatives, do not accurately predict results in humans—of the more than 80 HIV vaccines that have proven safe and efficacious in chimpanzees (as well as other nonhuman primates), all have failed to protect or prove safe in humans in nearly 200 human clinical trials, with one actually increasing a human’s chance of HIV infection.

Lives lost

Statistics show irrefutably that animal-based methods used in preclinical testing to select drugs for human use are unreliable. In fact, studies show that if you flipped a coin to guess how a human will respond to a certain drug, your prediction would actually be as accurate as if you tested the drug on a nonhuman animal. The U.S. Food and Drug Administration (FDA), the U.S. Department of Health and Human Services (HHS), and the pharmaceutical industry all acknowledge this. The FDA reports that 92 percent of drugs approved for testing in humans fail to receive approval for human use. This failure rate has increased from 86 percent in 1985, in spite of all the “advances and refinements” intended to make animal tests more accurate. In addition, more than half of the few drugs approved are later withdrawn or relabeled due to serious or lethal adverse effects in humans. For example, the arthritis drug Vioxx appeared to be safe in animal studies, but was withdrawn from the market in 2004 after causing over 60,000 deaths in the U.S. alone. In 2007, the FDA revealed that serious and fatal adverse drug events have more than doubled between 1998 and 2005.

Still, even if other species were in fact good models for human biomedical research, other factors would contaminate the results. Stress, routinely experienced by animals in labs, negatively influences the reliability of animal research data. Stress influences heart rate, pulse, blood pressure, muscular activity, and hormone levels and can modify the normal values of these variables significantly. In one study, researchers discovered that not only is stress a common factor for mice in labs—just having a researcher present can alter a mouse’s behavior—but they also experience “sympathy pains” for the mice surrounding them. “In other words, seeing another mouse in distress elevates the amount of distress the onlooker displays.” This unaccounted for and likely unobserved stress in research animals can significantly skew the interpretation and results of research data. In this case, the “average researcher, when testing for toxicity effects in mice for example, likely assumes that they are starting at a pain baseline [an assumed average level of pain], when in truth the surrounding environment is not benign and can significantly affect results.” Add to this the fact that some species like chimpanzees have been held in laboratory confinement for decades, used in multiple protocols, and as they are transferred from lab to lab, their records are filled with inaccuracies and omissions.

Economic costs

Animal research is a multi-billion dollar industry in which for-profit commercial interests have high stakes. This is one of the major reasons why the use of animals not only continues, but also is fiercely defended despite obvious limitations, dangers, and the reality that it may not help our battle against human diseases, and might actually hinder it. As an example of such financial motivation for its continuance, consider for example that in 2010, The Jackson Laboratory—“a leading mammalian genetics research center”—sold 2.9 million mice for a profit of $98.7 million. Investment in the procurement, handling, and upkeep of animals for labs is a highly lucrative enterprise for animal importers, breeders, dealers, cage and equipment manufacturers, feed producers, and drug companies. In line with that, the purchase and maintenance of animals in labs is very expensive. Rats, mice, and birds comprise over 90 percent of all research animals not because they are necessarily the best and most reliable animal models, but because, in comparison to many other species, they are relatively inexpensive to buy, easy to manage and maintain, and disposable without much public clamor or concern.

Although industry draws huge profits from it, there is an economic downside to animal research that directly affects public health and environmental safety. Relative to non-animal, alternative methods, live animal research is prohibitively expensive and time consuming. For example, the DakDak test (used to measure the efficacy of sunscreens in preventing skin damage) can provide data for five or six products at less than half the cost of testing one product in animals. The current “gold standard” for testing a chemical to determine if it is carcinogenic is the rodent bioassay, which takes up to five years from planning to evaluation and review, at a cost of up to more than $4 million per substance. In vitro screening allows companies to identify promising test compounds in a cost- and time-efficient manner before progressing to human trials.

The need for change

The massive effort needed to effectively screen environmental pollutants, carcinogens (substances that cause cancer), teratogens (substances that cause birth defects), and mutagens (substances that cause genetic damage), is a major and urgent challenge facing the U.S. today. From a strictly economic standpoint, it makes no sense to continue relying on animal safety tests to safeguard human health and the environment—even if relevant industry is getting rich from it. A battery of quick, reliable, and inexpensive in vitro tests is now needed to monitor adequately the thousands of new industrial chemicals and commercial products that continuously enter the U.S. marketplace every year. Given the scientific advances over the last few decades and the myriad alternative human-specific technologies available to researchers, remaining dependent solely or even predominantly on animal research and testing gives way to narrow-mindedness in scientific progress. Furthermore, this carries the strong potential of the exorbitantly high cost of  “lost opportunity” for more effective and timely paths to the treatments and cures desperately needed.

Since the founding of NEAVS, we have exposed and opposed the shocking cruelty of animal experiments, along with their wastefulness and irrelevance. NEAVS is not just anti-vivisection—but also pro-science and pro-alternatives which are scientifically superior.  Our message is clear: there is a better way to promote human and animal health and safety than the cruel, outdated, and ineffective use of animals in research, testing, and education. 

[1] Cimons, M., Getlin, J., & Maugh, T., II. (1998, May 6). Cancer Drugs Face Long Road From Mice to Men. Los Angeles Times, A1.