"The alternative would be human experimentation"

Animal testing is controversial. The suffering of animals stands in contrast to scientific knowledge: all medicines are based on experiments with animals. Although there are already alternatives, they cannot replace animal testing in the short term.

Animal experiments are as old as Western medicine itself. Experiments were already being carried out in ancient Greece. Almost all medicines that exist today were developed with the help of animal experiments. They were used to develop antibiotics, insulin and vaccines - as well as therapies and surgical procedures.

Corona vaccines, for example, would not exist today without animal testing: "The development of this vaccine and the fact that it was available so quickly is based on animal testing that took place many years ago, from basic scientific questions. This basic knowledge was necessary in order to develop a vaccine so quickly," says Christa Thöne-Reineke, Professor of Animal Welfare, Animal Behavior and Laboratory Animal Science at Freie Universität Berlin, in the ntv podcast "Wieder was gelernt".

In Germany, animal experiments are mainly carried out in basic research; according to the latest figures from the German Center for the Protection of Laboratory Animals (Bf3R), the proportion is 56 percent. The aim of basic research is to "better understand organisms and the development of certain diseases in order to develop good approaches for new therapies", explains Thöne-Reineke.

Animal testing banned for cosmetics

Animal testing is also used to research diseases such as cancer. Animals are also used to test how toxic chemicals are. This includes genetic testing on animals, such as cloning, as well as veterinary medicine.

Animal experiments are also an important part of the training of veterinarians: Students practise examinations and procedures on live animals. In addition, veterinary medicine at Freie Universität Berlin also uses video material, case studies and artificial plastic models to practice, the professor explains.

In other areas, however, animal testing is prohibited in the EU. For example, in the development of cosmetics and hygiene products or in armaments research. However, there are loopholes: the ban on animal testing in make-up, shampoo etc. only applies to ingredients that are used exclusively in cosmetics. Substances developed for other purposes fall under the Chemicals Act and may be tested on animals.

Drugs always tested on animals

However, anyone developing new medicines cannot avoid experimenting on animals, as this is required by law. Side effects are researched and whether the preparations work. There are no animal-free drugs. "Since every medical advance and almost all Nobel Prizes awarded in the field of physiology and medicine are based on animal experiments, it will not be possible to completely do without them in the foreseeable future," says Thöne-Reineke in the podcast.

Anyone wishing to carry out animal experiments in Germany must apply to and obtain approval from the relevant authorities in the federal states. The scientists would then have to demonstrate the scientific necessity and ethical justifiability, among other things. "If there is an alternative method, then the experiment may not be carried out at all," says the animal testing expert.

According to research by NDR, there have also been isolated cases of illegal animal experiments in German laboratories over the past two years, in 9 out of 16 federal states. Most of them in Lower Saxony. Illegal in this case means that some of the experiments were carried out without authorization. And that they were often carried out differently than authorized. For example, the animals were kept in cages that were too small, or more animals were killed than permitted.

Rodents and fish in the lead

The number of laboratory animals has fallen in recent years: according to Bf3R figures, 1.8 million animals were used in experiments in 2021. This is fewer than in previous years. 80 percent of these were rodents, mainly mice and rats, but fish also make up just over 12 percent. Even dogs are occasionally used for experiments. Around 644,000 animals were killed to examine their organs and tissues, 2 percent more than in 2020.

One argument that is repeatedly put forward by critics of animal testing is that the results are hardly transferable to humans. The animal rights organization Peta, for example, argues that 95% of new drugs found to be effective and safe in animal testing never make it to the market. For them, this is proof that animal testing is not useful for scientific reasons.

The German Research Foundation (DFG), on the other hand, writes that 70 percent of unexpected side effects of drugs can be discovered in animal models. "These are not even used clinically in humans," explains Thöne-Reineke. It is clear that a tiny mouse or rat is not comparable to a 75-kilogram human. "But there is a large genetic match, more than 95 percent."

Aiming for fewer animal experiments

The DFG describes it as a dilemma: the gain in knowledge for humans is associated with the burden on animals. Thöne-Reineke also sees no way out in the "Wieder was gelernt" podcast: "If we were to say now that we would do without it, but still want the same level of safety, then that would mean that we would no longer carry out animal experiments ourselves, but that they would be carried out elsewhere. If we completely abandon animal testing now, then we will end up doing human testing."

Animal testing has been regulated in Europe by an EU directive since the 1980s. It states that the member states want to move away from animal experiments. The three principles of replacement, reduction and refinement apply: replacing animal experiments and using methods in which animals suffer less or in which fewer animals are required. The EU member states must therefore promote alternative methods.

Such methods already exist: scientists are conducting research using cultured cells, artificial human skin or computer simulations. Researchers are also already able to recreate individual organs such as kidneys or livers in miniature form - organoids in technical jargon. A team of researchers from South Korea and the UK has used miniature lungs made from human lung tissue to investigate how the coronavirus infects the lungs.

"You need a battery of alternative methods"

The FU professor knows that there is no one special alternative method that can replace an entire animal experiment. "You always need a whole battery of different alternative methods because these models only cover partial aspects." For some years now, a lot of money has been spent on advancing alternative methods, so far mainly in toxicology, but now also in basic research.

It can take decades before these alternatives to animal testing are established. Thöne-Reineke also criticizes the lengthy approval process for these methods.

If scientists are one day able to recreate the interaction of several organs in the bloodstream and the immune system, as in real living beings, this could replace animal experiments. Experimental animals will therefore remain an important component of science for a long time to come.