Is animal testing necessary?

25 July 2019
Animal testing is a controversial subject. Every year on April 24th, World Day for Laboratory Animals, protests are held against the use of animals in scientific research. After all, isn’t it time we moved on from animal testing? The truth is that in some circumstances animal testing remains needed to save lives.

As scientists, animal welfare is one of our main concerns, so we understand the social worries about animal testing all too well. Animal testing is strongly regulated – rightly so -- and only implemented when no other alternatives are available. Obviously, researchers have to justify which experiments we do and why, but when new medical breakthroughs are reported, the important role animal research played is often forgotten or downplayed.

The Nobel Prize for medicine this year, for example, went to two groundbreaking scientific discoveries that revolutionized cancer treatment. Thanks to experiments on mice, scientists developed immune therapy, in which one’s own immune system is stimulated to recognize and attack cancer cells. Immune therapy could save the lives of over a fifth of all cancer patients!

The vaccine for Ebola, the virus that swiftly spread across West-Africa a few years ago, was also the result of animal testing. Between 2014 and 2016, over 10.000 victims of Ebola died, but according to the World Health Organization, the new vaccine could prevent epidemics of this magnitude in the future.

Claiming that animal testing is useless is clearly not accurate, even though not every treatment that is effective in mice will be equally effective in humans.


People that protest animal testing are, of course, not protesting medical progress. Many opponents claim that animal testing is easily replaceable and that scientists only use it out of complacency or financial considerations.

But these claims reflect little experience with the actual research practice. Animal testing is expensive, and every study involves a lengthy application procedure, in which a proposal is judged by an ethical commission. Just like animal-free testing methods, using animal models has its limitations. Animals are a lot like us, but at the same time there are some important differences.

The sense and nonsense of animal testing

Animal testing is not embraced with enthusiasm, but it remains necessary. Scientist constantly evaluate the usefulness, necessity, and points of improvement of animal models.

Beyond the primary reason of animal welfare, there are several practical reasons to avoid animal testing and a lot of effort is put in the pursuit of alternatives. Whenever possible, human model systems are used to make the transition from lab animals to humans easier. Organizations like the Dutch ‘Proefdiervrij’ for example, gather funds to specifically support research into alternatives. They do this together with scientists, entrepreneurs, and the government.

Thanks to increasingly powerful computer simulations, organs can be mimicked virtually. Digital models or screening methods of this kind are already used for chemical safety screening, which limits one of the most common types of animal experiments. 

In fundamental research as well, important progress is made. Late last year, the Chan Zuckerberg Initiative (the philanthropic project of Facebook founder Mark Zuckerberg and his wife Priscilla Chan) announced that it will invest a million dollars in the development of a new chip to study the mechanisms of Parkinson’s disease. This chip, which will be developed by Leuven scientists, will contain artificial brain circuits, constructed using cells of people with and without Parkinson’s.

When an alternative method is available, scientists are legally required to use it. Unfortunately, not all animal testing can be replaced by alternatives yet.

Where to go from here?

If you ask me, we’ll never be able to completely replace animal testing. But that doesn’t mean we shouldn’t continue to reduce, replace, and refine our methods whenever possible. No one engages in animal testing for fun, certainly not scientists. The fact that some people think this, bothers me a lot.

This is why I find it so important to continue the conversation on animal testing. There are so many misunderstandings, and we as scientists are partly to blame. Because animal testing is such a controversial topic, it is often avoided in communication and outreach. As a result, opponents and proponents are often having different conversations about both the problems and solutions.

So, let’s not avoid the conversation about animal testing, and reflect on the impact animal testing has on our own lives. 

To truly contribute to a world free of animal welfare infractions, don’t protest against research, but help scientists work on a better, healthier world for animals (including humans).

Want to learn more about animal testing? Read our Fact Series 


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 Liesbeth  Aerts is science communicator at the VIB-KU Leuven Center for Brain & Disease Research. 

She is also part of Infopunt Proefdierenonderzoek, an initiative that provides nuanced information on animal testing for the public. 

She has performed research at VIB and KU Leuven, and the University of New South Wales in Sydney, Australia.