As the medical industry has developed with industrialization, animal testing has become a popular way to test medicines for effectiveness. However, the differences in genes and diseases between humans and animals raise questions about the validity of animal test results. Animal testing can also lead to unexpected side effects, as seen in the thalidomide scandal, and many animals are sacrificed, which raises ethical issues. Alternatives such as in vitro studies and mathematical modeling are becoming increasingly viable, and there is a growing consensus that we need to reduce our reliance on animal testing.
With industrialization, the development of new drugs and the healthcare industry has grown by leaps and bounds, leading to a variety of ways to evaluate the effectiveness of medicines. At the same time, the validity of animal testing, the most widely used method of evaluating medicines, is being questioned. Animal testing refers to experiments conducted on all animals except humans, and approximately 200 million animals are sacrificed in experiments around the world every year, with an estimated 3 million animals sacrificed in Korea alone. This is because many countries, including Korea, use animal testing as a standard for evaluating medicines, but is it a valid method?
In fact, the difference in DNA sequence between humans of different genders, races, and birthplaces is less than 1%, while the difference in DNA between monkeys and humans, which are said to be similar to humans, is about 16%. In addition, the diseases that humans and animals have in common are only about 1.16% of all diseases, and most cancers, AIDS, dementia, etc. are diseases that only appear in humans. “The history of cancer treatment in humans is the same as the history of cancer treatment in mice, and we’ve been treating cancer in mice for decades, and frankly, it hasn’t worked in humans,” said Dr. Klausner of the National Cancer Center. This raises the question of whether the results of experiments in animals with large differences in genetic sequences and few diseases in common can be applied to humans.
The problems with animal testing aren’t just theoretical; they’re real. Thalidomide, developed in Germany in 1953 to prevent morning sickness in pregnant women, was proven safe in animal studies and exported to more than 50 countries, where it was dubbed a “miracle drug.” However, its use resulted in 12,000 deformed babies being born within a year. Side effects that were not detected in animal studies were seen in humans. The pharmaceutical company claimed that tests on rats, rabbits, pigs, and others showed no harmful effects, but it was eventually discovered that thalidomide’s optical isomer differences caused severe teratogenic side effects only in humans.
The thalidomide case isn’t the only example of a drug behaving differently between humans and animals. For example, penicillin, a common treatment for bacterial diseases, is beneficial to humans but can be poisonous to guinea pigs. Morphine, a sedative for humans, is a stimulant for cats. These different effects of drugs on different animals make it inappropriate to extrapolate the results of animal testing to humans.
There is also the problem that animal testing is inefficient in terms of the results compared to the cost. “As the author of ‘Animal Testing in Greed and Arrogance’ puts it, “Rats are animals that vomit up papers when they’re drugged,” and while animal testing is often used in academic research, its effectiveness is questionable. While 200 million animals are used in animal testing each year, only 25 new drugs are registered with the U.S. Food and Drug Administration (FDA) each year. The practice of repeating ineffective animal tests to write papers has the potential to lead to a second thalidomide scandal by disseminating faulty research results.
Another issue is that animal testing should be banned from an ethical standpoint. Animal testing is justified by applying different ethical standards to animals and humans. The ethical basis for animal testing is the presence or absence of “moral will” – the willingness to uphold norms that are based on social concern, public opinion, or custom. Two contradictions arise here. First, newborn babies and brain-dead people are excluded from animal testing even though they are not considered to have the capacity for thought or moral will. This shows that the ethical standards of animal testing do not serve as a basis for distinguishing between humans and animals. Second, animals such as monkeys and dogs are still used as scapegoats in experiments, even though research continues to show that they have moral agency.
In addition, animal testing is often conducted unnecessarily and in violation of regulations. The Code states that “research involving animals should be conducted after considering whether any potential adverse effects on the welfare and well-being of the animals are justified by the educational value or scientific importance of the research, and that researchers should consider the welfare of animals in the planning and conduct of research and treat animals with respect.” However, in practice, experiments are conducted in violation of the Code. For example, even in the early 21st century, dogs and monkeys were exposed to cigarette smoke by drilling holes in their throats, despite the clear harms of smoking. This hardly fulfills any educational value or shows respect for animals. Animal testing needs to be reevaluated not only for its practicality, but also for its ethics.
Today, many excellent alternatives to animal testing have been developed. In vitro studies and mathematical modeling are two examples. In vitro research involves growing target organs in a test tube to see if a drug causes side effects. Certain cancers that only occur in humans cannot be tested on animals, so cancer cells are metastasized to the target organ in a test tube. Mathematical modeling is a method of predicting whether a drug will cause side effects in humans by running mathematical formulas through a computer. In fact, the side effects of thalidomide that were not identified in animal testing were identified through mathematical modeling. With these practical and ethical alternatives, it is unreasonable to insist on animal testing.
While animal testing has certainly contributed to the advancement of medicine, it has also claimed victims in incidents like thalidomide along the way. Preventing a second Thalidomide should be a priority, as we never know when a new drug’s side effects will be discovered. Of course, stopping animal testing now would temporarily set medicine back, but blindly pursuing animal testing with its ethical and practical limitations would likely lead to a second or third Thalidomide. Therefore, animal testing should be gradually reduced and alternative research methods should be expanded. In addition, when animal testing is unavoidable, experimenters should strictly follow the Code of Conduct and take the utmost responsibility for the animals. As a society, we need to strictly manage animal testing regulations to ensure compliance.
