Animal experiments are performed in Belgium and in many other countries. These experiments are performed on animals, in most instances because it is impossible to perform them on humans. Animal experiments are performed for scientific – particularly biomedical – research, for the testing of the safety of certain consumer products and for the testing of the safety of chemical substances. In some cases the animal experiments are performed specifically due to legal requirements.

Small rodents, particularly mice and rats, are used for the vast majority of animal experiments. The use of animals for the testing of certain consumer products is a sensitive issue - and rightly so. A number of alternatives have been developed over the years, particularly for these types of animal experiments. These are primarily tests that are performed on cells that are grown in test tubes.

On top of normal cell cultures as an alternative, there are now also certain stem cell derived human cells, 3D cell cultures, organoids and mini-organs on a chip that can be used to answer specific research questions. These are more complex models than normal cell cultures and can therefore in certain cases provide answers to more complex research questions. So depending on the question you need to answer these more complex tissue culture models are a valid alternative to the use of animals. But also these new models cannot fully replace animals. They are a step in between simple cell cultures and the complete animal.

Animal experiments are unavoidable if we want to make the necessary progress in medical-scientific research.

Medical-scientific research aims to contribute to the improvement of health care. It aims to contribute to the development of new methods to prevent, diagnose and treat diseases. In order to achieve this, it is important first to gain a better understanding of the human body in sickness and in health. The various molecular mechanisms that cause disease need to be unraveled. This is currently not possible without some use of animals. After all, many diseases are a complex interaction between various components, cells and tissues, in a three-dimensional structure. This interaction and communication cannot always be copied in cell cultures and that makes animals - at least in part - essential to understanding these complex interactions. In many cases so-called animal models are used: animals in which certain disease symptoms are elicited genetically, chemically or in some other way. The human disease is copied. Such experiments provide a lot of relevant information and many of the new drugs being marketed today were in part created thanks to this process.

The use of animals in medical research: infographic

It is important to realize that animal models are indeed just models. They often cannot fully represent or copy the human condition. But the animal model will provide relevant information where the genetics and molecular pathways are similar. One should also realize that the alternatives in the form of cell cultures or more complex alternatives such as organoids or organs on a chip are also just models. They also have their limitations and the questions that one can answer with them are often more limited.

Use of lab animals is minimized by applying the three Rs (replacement, reduction, refinement)
The “three Rs” are a central concept in the use of animals in scientific research. They stand for Replacement, Reduction and Refinement of animal experiments. These principles have been enshrined in the animal welfare legislation and should always be applied when considering an animal experiment.

This principle means that - wherever possible - an animal experiment must always be replaced by an alternative that does not require animals. For example, an experiment using cells in a test tube as an alternative.

This principle entails that when you perform an animal experiment, you should always use the lowest possible number of animals that will still give you a scientifically and statistically relevant result.

This principle entails that for each action that you want to perform using a lab animal, you should determine whether there is another way of performing this action so that the animal suffers less hindrance or pain. For example, this means that you should use anesthetic where possible, or that you should replace a large needle with a small one. But there is much more to it than that.

Alternatives to animal experiments have been in development for many years. And as already described above the number of alternatives is growing and they are becoming more complex. Especially for toxicological research quite a number of valid alternatives have been developed. Various organisations and institutes are involved in the further development of alternatives, including:

More information about the how and why of animal experiments