Dr. Thomas Hartung, a well-known toxicologist at Johns Hopkins University and advocate for the development of alternatives to the use of animals, as well as a mentor to a current NAVS/IFER fellowship recipient, recently published an article in ALTEX summarizing the main limitations of experimenting on animals. As Hartung notes, “[Animal experiments] come with shortcomings, and their true contribution is often overrated.”
Following are five reasons why scientists should stop relying so heavily on animal models:
- Animal experiments are not very reproducible. This often stems from lack of bias-reducing measures, poorly planned experiments, inappropriate statistical tests, poor reporting on animal attrition (why animals are dropped from studies) and poor reporting of pain relief in lab animals.
- Animal experiments are expensive and time consuming. Hartung notes that “costs and duration of toxicological studies are clearly prohibitive to satisfy societal safety needs,” in large part because animals are experimented on over a long period of time, during which researchers collect and analyze a lot of data to ensure that they are not missing any harmful effects. Using other approaches, such as cell-based models, could help scientists get results faster and cheaper.
- There are ethical concerns with animal experimentation. What entitles humans to experiment on animals and inflict pain upon them?
- Animal experiments are not even predictive of other animal species, let alone humans. Experiments performed in rats do not predict what happens in mice. Experiments in one strain of mice may not predict what is seen in another strain. Therefore, we shouldn’t assume that animals will be able to accurately predict what happens in humans.
- Animal models do not reflect human diversity. Even if animals could be predictive, to which humans would the data be accurately applied, considering the differences among humans?
Some in the scientific community have suggested investing more time and effort to improve the design of animal experiments, or even the animal models themselves, to address some of the issues raised above. But these resources would pay much higher dividends if they were directed to more human-relevant research, including work with human cell lines, stem cells and tissues, computational models, and even humans themselves.
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Source: Hartung, T. “Opinion versus evidence for the need to move away from animal testing,” ALTEX, 2017