April 24: World Day for Laboratory Animals
Manuel Van den Broucke, sports, society and politics correspondent, April 24, 2025
Types of Experiments Performed on Animals
Toxicity tests are the most common: they involve administering chemical substances to assess their health effects, sometimes up to lethal doses, as in LD50 tests. Other research uses animals to study the development and treatment of human diseases such as cancer, diabetes, Alzheimer's, Parkinson's, or viral infections like HIV or SARS-CoV-2. In pharmacology, animals are used to test the efficacy and side effects of new drugs before human clinical trials. Many medical treatments, such as insulin, antibiotics, and vaccines against polio, hepatitis B, and HPV, were developed through animal testing.
Alternatives to Animal Testing
Among the most advanced methods are cell cultures, which allow researchers to observe the behavior of human cells in a controlled environment, particularly to test the toxicity or efficacy of substances. Organoids, mini-organs grown from stem cells, replicate specific functions of the liver, heart, or brain, and are used to model certain diseases. Computer simulations, or in silico methods, are also increasingly used to predict how a chemical compound will affect the body. Microfluidic chips, or "organs-on-chips," simulate the reactions of human tissue without using a whole organism. In cosmetics, tests on artificial skin or cornea tissue have replaced animal testing in several countries.
Legal Framework: What Does the Law Say?
In Europe, Directive 2010/63/EU governs the use of animals for scientific purposes. It requires applying the 3Rs principle: replacing animals wherever possible, reducing their numbers to the strict minimum needed, and refining procedures to limit pain and stress. In the United States, animal testing is governed by the Animal Welfare Act and overseen by the USDA, though the law does not cover all species, notably rodents. Additional guidelines, such as the Guide for the Care and Use of Laboratory Animals, apply at institutions funded by the NIH.