Cijfers over dierproeven

Figures on animal testing

A total of 81.468 animal experiments were carried out at WUR in 2021, an increase of 33% compared with 2022. This more than offset last year's sharp drop. These are experiments that fall under the Wod and that were completed in 2021.

Annual fluctuations in the number of animal experiments were mainly seen for pigs, chickens and fish and, to a lesser extent, mice. This is due to large, long-term research projects that took place into the health and welfare of pigs and poultry, into more sustainable fish farming, and into the role of mice in the transmission of Lyme and other diseases.


Wageningen graduates may be required to conduct animal experiments as part of their work. WUR therefore believes it has a duty to teach students about responsible animal testing and the ethical aspects associated with the use of test animals.

Any students who are opposed to animal experiments on ethical grounds or who do not wish to use materials taken from animals during practical sessions may choose to follow a dissection-free variant of the compulsory classes. This is not however possible for subjects in the specialisation phase of the programme, although students may choose subjects in which they do not have to carry out animal experiments

Which animals fall under the Wod?

The Wod applies to animals that are used for scientific or educational purposes and that undergo pain or suffering as a result of an experiment. The Act applies to vertebrates, including the independently feeding larval forms of fish and reptiles, the foetal forms of mammals from the last trimester of their development, and cephalopods. Some animals that are housed at WUR are not covered by the Wod and are therefore not included in this annual report. This may be because they are kept for breeding, or as commercial animals, or because they are not exposed to pain or suffering during the experiment, for example because they are only kept for observation.


The ‘rehoming’ of test animals is permitted under certain conditions. WUR follows the Code of Practice drawn up by the Netherlands National Committee for the protection of animals used for scientific purposes for the rehoming of test animals.

Cats that are kept at WUR are ‘retired’ after seven years and put up for adoption. Using a detailed questionnaire, the right cat is coupled to the right owner. The cats that are housed at WUR are mainly used for behaviour and food research. They receive a lot of attention from students and carers and are therefore well-socialised and suitable for adoption.

Wageningen Research (WR)

Most of the animal experiments carried out at Wageningen Research (WR) in 2021 were used in research into the protection of animal species (76%), primarily the monitoring of fish stocks. This was followed by applied and translational research (20%), primarily into animal welfare and animal health. After this came statutory testing (3%), mainly batch potency testing (testing the potency of batch-produced medicines) and bioaccumulation (accumulation of (hazardous) substances in an organism).

WR numbers 2016-2020

Wageningen University (WU)

Most of the animal experiments carried out at Wageningen University (WU) in 2021 were for applied and translational research (69%), in particular research into animal welfare. This was followed by fundamental research (27%), in particular into the immune system, then educational purposes (3%).

WU numbers 2016-2020

Animal species

Almost three quarters of all animal experiments carried out at WUR are on fish (72.5%). These experiments are mostly for statutory fish stock monitoring, within the research theme ‘protection of animal species’. This is followed by chickens (domestic fowl 13.8%) and mice (3.8%). Chickens and cattle are mostly used for research into animal welfare. Not all of the animals in this overview are housed in WUR facilities. Research for the conservation or monitoring of wild populations can only be carried out using animals in the wild. Some animal experiments are also carried out on experimental farms, for example on chickens.

Click on the image to enlarge it.

Level of suffering at WUR

The tables show the level of suffering experienced by test animals at WUR in 2021. The expected level of suffering is assessed as part of the project plan, and again when the project has been completed. The table shows the actual levels of suffering. Various factors are taken into account to determine this, such as the pain and fear that a particular procedure causes, or lasting harm to the animal. Animal suffering is assessed cumulatively. For example, different processes may be carried out within a procedure that each cause ‘light suffering’. However, the total amount of suffering during the entire procedure may be categorised as ‘moderate suffering’.

Terminal assessed animal experiments

Animal experiments are assessed as terminal if the animal is killed to examine tissues or organs. The animal does not therefore experience pain or discomfort during a procedure.

Light suffering

Light suffering means that there is a risk of slight pain or discomfort for a short period. These activities and procedures do not therefore significantly affect the animal’s well-being. These could include the administration of and waking from a light sedation, taking a blood sample, or administering a substance through a tube. Housing social animals such as mice or chickens in isolation is also regarded as light suffering.

Moderate suffering

In the case of moderate suffering, there is a risk that the animal experiences a moderate level of pain or discomfort for a short length of time, or slight pain or discomfort for a longer time. Examples of procedures that cause moderate suffering are frequently taking blood samples, surgery with good post-operative pain management, or the solitary confinement of social animals for several days to several weeks (depending on the species).

Severe suffering

Severe suffering is the highest category of suffering. The animal is likely to experience severe suffering during an experiment that seriously harm the animal’s well-being. Examples of procedures that cause severe suffering are exposure to a deadly disease associated with prolonged pain and suffering or the long-term housing of a social species in solitary confinement. Most of the animals at WU (79%) experience mild suffering. At WR 50% of the animals experienced mild suffering and 50% experienced moderate suffering in 2021.

Relatively more experiments that cause moderate suffer-
ing are carried out at WR. One reason for this difference is
the nature of the experiments that are carried out at WR.
These include experiments for research into animal
disease, which in some cases require animals to be
infected with the disease in order to study it.

Click on the image to enlarge it.