History and trajectory of animal experimentation in the US

Emily Carter

For centuries, vivisection, the use of non-human animals in medical science, has progressed biomedical research, but not without controversy. Even in the 3rd and 4th century, philosophers were divided on their stance on how to treat animals. According to the Oxford dictionary, vivisection is defined as: “the practice of performing operations on live animals for the purpose of experimentation or scientific research (used only by people who are opposed to such work).”

The word vivisection may seem to be a word only used by animal activists, but it has also been used by the National Institute of Health in a review regarding the extensive history of the use of animals in medical science. The review introduces the motivating philosophies behind animal experimentation, which began in ancient Greece. Early Greek scientists, including Aristotle, performed experiments on live animals to better understand the anatomy and physiology of humans. However, the Greek school of thought was replaced by opposing viewpoints that rejected animal studies for medical use on grounds of cruelty and uselessness. The Empirical school, for instance, believed that the pain and death experienced by the animals would distort the normal appearance of their inner body.

Essentially, the question of animal ethics has two sides: either you are for animal testing or against it. Some people fall in the middle, but usually those against animal testing believe that the benefit to humans does not justify the mistreatment of animals or that results from animal testing do not apply to humans because of differences in physiology. Those in support of vivisection view humans as superior to animals and believe animal experiments to be necessary for the advancement of humans. 

People who oppose vivisection in the US have made it known how they feel, especially after the opening of the first animal experimentation laboratories in the 1860s and 1870s. About 150 years ago, the first anti-vivisection law passed in Great Britain. The Cruelty to Animals Act was constructed to regulate the use of animals in scientific research. With no sign of similar legislation occurring in the US, a group of Philadelphians led by two women, Caroline Earle White and Mary Frances Lovell, decided to create the American Anti-Vivisection Society (AAVS) in 1883. AAVS’s mission is to abolish vivisection in the US by educating, creating public awareness, speaking for the prohibition of animal experimentation, advocating legislation, and proposing alternative research methods. 

At AAVS’s conception, the Progressive Era was underway, and the animal welfare movement fit perfectly with the goals of the Era. In a time of increased social and cultural awareness, people were focused on improving society, especially the lives of the weak and voiceless. 

The anti-vivisection movement likely lost and gained some supporters after a pharmaceutical scandal unveiled the need for testing after over 100 people died from a drug called “Elixir Sulfanilamide.” The chief pharmacist and chemist were unaware of the drug’s toxicity, which ultimately led to the passing of the 1938 Federal Food, Drug, and Cosmetic Act which required the testing of drugs on animals before they could be administered and marketed to humans. With the explosion of prescription drugs that followed, animal testing became a new norm. However, there have always been people who are dedicated to the fight for justice for animals, which continues today.

In recent years, innovators have been developing alternatives in order to minimize animal experimentation so that all of our animal friends are able to live their fullest and happiest lives. In addition to maximizing animal well-being, the antivivisection movement is also fueled by people who do not see the benefit of spending $15 billion a year on animal testing, which is approximately how much the U.S. government spends annually. 

More than 60 years ago, the 3 R’s of animal testing were introduced: replacing, reducing, and refining. Replacing is a test method that favors biochemical or cell-based systems, which involves replacing one animal species with another that is less developed (such as replacing a mouse with a worm). Reducing means decreasing the number of animals required for testing to a minimum, and refining means enhancing the well-being of the animal being tested by eliminating pain and distress. Since 1973, the overall trend of animal use in science has decreased by almost half. In 2017, about 750,000 animals were used in U.S. research, down from the over 1.5 million in 1973. 

Scientists are working towards using in vitro systems that are biochemical or cell-based, as opposed to in vivo methods that involve experimentation inside of a living organism. Clinical studies utilizing in vivo methods can take years to complete, and testing a single compound can cost more than $2 billion. During this research process, animal lives are lost and results from the animal models used may not be transferable to humans. 

For these reasons, in vitro methods are becoming more important. In vitro methods have proved to be very successful in identifying some chemical hazards, such as eye irritants and substances that cause dermatitis. However, inventing in vitro methods to test whether a chemical can result in cancer or birth defects is more difficult because of the biological complexity of the processes involved. 

Thanks to brand new innovation, an organ chip, the ability to test any drug and model any disease, may be a new norm. Organs-on-Chips were developed at Harvard’s Wyss Institute, and are now being further researched by a startup company called Emulate. These devices offer a unique structure that imitates relevant pathways in the body crucial for understanding drug delivery, disease development, the impact of environmental exposures (like smoking) on cellular tissue, and the role of the microbiome in health and disease. Organs-on-Chips can be personalized by using someone’s cells to line the chip. The chips can also be connected to mimic entire organ systems. 

In conclusion, the current trajectory of medical science is geared towards minimizing animal use for the sake of economics, ethics, and efficiency. Ancient philosophies regarding the way medical methods should be tested must be evolved and reconsidered to suit current needs. Medical innovation has come a long way in terms of the use of animals, and is expected to progress even further with new innovations such as the organ-on-chips which do not rely on animals.

Sources: American Anti-Vivisection Society, Faunalytics, National Institute of Health , USDA, Wyss Institute at Harvard University