Why are animals used for research in modern science? Well, that’s because nowadays you cannot experiment on humans as Edward Jenner did back in 1796. That leaves us with animals because of three very essential reasons –
- Animals are biologically very similar to humans. Mice share more than 98% DNA with humans!
- Animals are as susceptible to many diseases as humans like cancer and other infectious diseases.
- The short lifespan of animals makes them an attractive model because they can be studied throughout their whole life span and across several generations. This is especially useful to understand genetic diseases.
Animals have been an integral part of science and research with their involvement seen as early as the 2nd to 4th centuries by the Greeks. But considering the events after the medical revolution in the 19th century, many biological discoveries have been because of the use of animal models. For instance, in the 1880s, Louis Pasteur convincingly demonstrated the germ theory of medicine by giving anthrax to sheep. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning.
To date, scientists use animals to understand human conditions and ways to treat them. Animal experimentation is also used for many biomedical research activities, such as pharmaceutical studies and biotechnology. Modern biomedical research makes use of animals like nematodes, mice, zebrafish, and non-human primates such as marmosets and macaques, but statistically, the most used animals are the mice. However, animals like pigs, hamsters, dogs, sheep, and many more are also reported.
This shows the essentiality of animals for the progress of the field altogether. However, their importance fails to hide the baggage of limitations they carry. There are a multitude of cons associated with using animals for research, of which two are of utmost importance –
In pharmaceutical testing, candidate drugs that show potential to treat a specific condition are tested on animals to make a prediction of how the drug will act in humans. However, this has been highly inaccurate just because of the fact animals process chemicals differently than humans. For instance, chocolate is lethal for a dog but safe for consumption and indeed a pleasure food for humans.
This unreliability of animal experiments can cause human suffering because imprecise results may result in clinical trials of harmful substances, thereby exposing patients to unnecessary risk.
Economically unfeasible –
Animal testing not only takes months to be completed but also cuts a big hole in the pockets of researchers and funding agencies. According to 2005 data, in the EU there were 1,026,286 animals used for various types of toxicology testing. This cost a whooping € 619,699,000 (610 million euros)! Moreover, according to Humane Society International, of late, it costs hundreds of thousands and sometimes millions of dollars per substance examined.
Animals are still used for research despite these limitations since there is no substitute for the complex functions of a living, breathing, whole-organ system with pulmonary and circulatory structures as in humans. But hold on! Researchers are developing newer models like 3D cell culture, 3D bioprinting, organ-on-a-chip which can address all the limitations of animal models. One of the main research areas at Nanomedicine Research Group is towards developing these alternatives to animals for drug evaluations in the pharmaceutical and cosmetic industries. With more standardization, characterization, recognition, and awareness, we will slowly transit from animal testing to using newer models in the coming decades.
However, we can’t write off animal testing in research yet! Throughout the recent pandemic, we saw the value of animal testing in understanding the virus and developing a vaccine for it. With significant advances in alternative models, animal testing is certainly going to be minimized or possibly replaced by newer and more effective models like in-vitro 3D models. As a parallel, this can be compared to the current transition from petroleum to electric vehicles and to previous transitions such as the change from Web 1.0 to Web 2.0.