News

Dr Melanie Seiler

Published: 20 September 2023

Researchers still want to continue using the macaque species

In 2022, the International Union for Conservation of Nature (IUCN), which regularly updates the Red List of Threatened Species, classified long-tailed macaques as endangered - the second highest threat category (1). This means that due to the massive decline in the number of monkeys in the wild in recent years, the survival of the species is at high risk. The IUCN considers this to be caused not only by the degradation of the natural habitat but also by the use of these animals for medical research. Now researchers are calling on the IUCN to revise its assessment, since drug safety could not be guaranteed without testing on monkeys (2). The German association Doctors Against Animal Experiments regards this as a call that is hard to beat in terms of ignorance and irresponsibility.

Long-tailed macaques (Macaca fascicularis), also called Crab-eating macaques, are the most frequently used non-human primate species in animal experiments. According to official statistics, 1,886 monkeys were used in animal experiments in Germany, of which 1,723 were long-tailed macaques (3). Animals of the species are mainly used in toxicological tests - this means that the animals are administered substances to test them for toxicity. For example, Germany's largest "monkey consumer," the company Labcorp (formerly Covance) in Münster, Germany, also poisons pregnant monkeys to test for effects of substances on their unborn offspring. "The transferability to humans is not given due to the species differences. Although often claimed by research institutions, there are no legal regulations mandating the use of monkeys in the cruel tests," states Dr. Melanie Seiler, primatologist and scientific officer for politics & law at Doctors Against Animal Experiments. In contrast, the safety of drugs can be tested in a way that is safe for humans through modern research methods such as the organ-on-a-chip technology, which can test the impact of substances directly on human cells (4).

Although long-tailed macaques are also bred in Mauritius, China, Cambodia and other countries, these by no means cover the needs of the laboratories. According to EU law, since 2022 only F2 generations, i.e. the grandchildren of animals from the wild, are allowed for use in animal experiments. However, this can hardly be verified in practice in the case of imports. In recent years, massive poaching of the monkey species has been documented several times by investigative research (2,5). Since prices of up to 35,000 US dollars per animal are now being called for, the illegal trade represents a lucrative business (6). Thousands of animals have been documented to have been captured from the wild both in their natural habitat in Asia and in Mauritius, either to serve as breeding animals in local monkey breeding farms, or to be shipped directly to animal research facilities worldwide.

"The fact that parts of the research community are seriously demanding that the IUCN retracts the objective classification of the macaque species as threatened in order to be able to continue conducting experiments on them is outrageous. Instead of finally taking this as a reason to shift research towards the already existing animal-free and human-relevant approaches and to develop them further, the possible extinction of the entire species is accepted here," Dr. Seiler comments on the complaint of the animal experimenters to the IUCN.

"How do the researchers plan on continuing their work after the species becomes extinct? Will we fall back on the next monkey species until its population is also endangered? We urgently demand a rapid rethinking of the researchers and call on them to become aware of their responsibility. It is absolutely incomprehensible that with the already existing excellent animal-free, human-relevant methods we are still relying on an absolutely outdated system, and that we risk the extinction of an animal species for it", says Seiler.

Long-tailed macaque in its natural habitat. (Photo: Adobestock)