In the Netherlands laboratory animals are used for research purposes. For example to develop new drugs, to carry out safety tests for new substances, or to learn more about the human body. By law, an animal experiment is only allowed if the goal of the experiment cannot be achieved with a non-animal method. All animal research must comply with the 3R principle of Replacement, Reduction and Refinement.
What is an animal experiment?
An animal experiment is a procedure in which an animal is used for research purposes and experiences pain, fear, distress or lasting harm equeal or higher than the insertion of a needle through the skin. These harms to the animal are collectively described as ‘suffering’, or ‘severity’. Research that causes too much suffering is considered an animal experiment. In the Netherlands, animal experiments must comply with the strict requirements of the Experiments on Animals Act (website in Dutch). This Act encompasses all vertebrates (mammals, birds, reptiles, amphibians and fish) and cephalopods (squids and octopuses).
What are animal experiments used for?
We conduct animal experiments for various reasons. For example, many new medicines and foods are tested on laboratory animals before they are allowed to be given to humans. This enables us to investigate if they are safe and effective. But researchers also conduct animal experiments to discover more about human or animal biology, for example to learn how diseases arise, so they can develop suitable treatments. Sometimes, laboratory animals are also needed for educational purposes. For example, to train veterinarians and surgeons. Or they are used to study animal diseases in pets, farm animals or wildlife.
Animal experiments are classified into a number of main areas of application or research objectives. These areas of application and objectives are described below.
Applied research mainly focuses on applying knowledge into practice, while fundamental research involves collecting basic knowledge about biology and the processes inside the body. Both types of research are used, for example, to study diseases in humans or animals. Such as cancer, cardiovascular diseases, respiratory diseases, muscular diseases, diseases of the digestive system or brain diseases. This research is carried out to learn how these diseases arise and how they can be treated. Sometimes, fundamental research needs to be carried out before a potential new treatment can be developed. For example, this fundamental research could involve studying the genes that are involved, or the physical processes that are altered by a disease. This information can later be applied to develop targeted treatments for the disease. Fundamental research and applied research are therefore often combined in various research projects.
To protect the health of humans and the environment from the hazards of chemicals and other substances, the law requires certain regulatory research to be carried out. Such research often involves animal experiments. Examples are quality control studies during substance production and drug safety testing (both during development and production). Studies are also required out to determine whether (novel) substance are potentially harmful and in what quantities.
Sometimes biological products are produced by, or originate from living organisms (unicellular organisms, plants or animals). This may involve the application of biotechnology. These products are used in humans and animals to prevent or treat diseases. Biological products are used to develop vaccines, hormone preparations, serums and antibodies. The law also requires the quality of biological products to be tested, and this often involves animal experiments.
This type of research focuses on the health of plants, water and the soil. Examples are studies into the effects of fishing on marine species, or research into the effects of soil pollution on wildlife. These studies require environmental research (such as soil tests), but also research into humans and animals. Sometimes it will suffice just to count how many animals are present, which is not classified as an animal experiment. However, if the animals experience suffering from the scientific procedure(s), for example if they must be captured in order to take blood samples, then this is considered an animal experiment.
Field biology involves research that is conducted to answer questions about animal ecology by studying animal behaviour and distribution. The aim is to ensure that wild animals can live safely and healthily in their natural environment. This involves studying aspects of their environment, such as their sources of food, territory and how they hunt and eat. Physiological characteristics such as energy consumption, the immune system and hormones can also analysed, as well as how they interact with others of their species. This knowledge is used to protect wildlife species in the Netherlands and maintain sustainable populations.
An important part of this research involves attaching transmitters to the animals. In this process, the wild animal is captured, lightly anaesthetised and a transmitter is inserted. This involves a similar amount of pain and distress to microchipping a pet. The transmitter can also be attached to the body with an adhesive or a collar, which sometimes also requires the animal to be briefly anaesthetised. After placing the transmitter, researchers can learn more about the animal’s behaviour in its habitat, or how it overwinters or migrates, for example.
It is sometimes necessary to train staff of academic institutions or certain vocational courses to work with animals. This is only allowed if it concerns unavoidable (animal) work and the relevant establishment or project licences have been issued. This includes training and education provided to those who work with laboratory animals, or practical training for students of veterinary medicine or veterinary assistants. Sometimes, a researcher may have to teach a specific procedure to another researcher.
Animal-free alternatives are becoming increasingly available, which minimises the need to use live animals in education. For example, students can practise the technique of suturing on a chamois cloth, or they can watch videos that demonstrate how to perform procedures on animals. Students often first train on dead animals or plastinated specimens (these are dead animals that have been preserved by injecting silicone into the body).
Genetically modified animals are animals whose DNA has been altered with a special technique, or animals whose DNA has changed spontaneously. Animals with specific modifications become suitable for certain types of research. Some studies involve the use of genetically modified animals to find out how genes affect inherited diseases. Genetically modified animals are also bred for research into cardiovascular disease, cancer or brain abnormalities.
Breeding genetically modified animals is considered to be an animal experiment if the genetic modification could affect the welfare of the animals, for example because they have retarded growth, develop weaker muscles or tumours, or lose their fur.
Breeding genetically modified laboratory animals is specialised work and requires a lot of knowledge of genetics and breeding techniques. In 2015, the NCad published an advisory report on the breeding of genetically modified animals. We recommended that each animal facility should have a dedicated breeding coordinator. These coordinators must monitor the quality and application of the technology involved in breeding these laboratory animals.
Who is allowed to carry out animal experiments?
Only specialized trained staff members are allowed to carry out animal experiments. They mostly work for:
Research universities or universities of applied sciences
University hospitals
Research institutions
Pharmaceutical companies
Contract Research Organisations (CROs).
Before a company or institute is allowed to conduct animal experiments, the organisation must be granted an establishment licence by the Netherlands Food and Consumer Product Safety Authority (NVWA). An animal experiment licence is also required for each separate research- or educational project. In the Netherlands, the only body that may issue these licences is the Central Authority for Scientific Procedures on Animals (website in Dutch).
Laws and regulations
Animals cannot protect themselves. This is why there are national and international rules governing the welfare of laboratory animals. For example, any organisation wishing to conduct animal experiments must first obtain a licence. Moreover, the suffering of laboratory animals has to be minimized as much as possible.
In 2010 the 2010 European Directive on the protection of animals used for scientific purposes (2010/63/EU) was published. This directive contains rules to ensure the protection of laboratory animals in Europe. For example, it only permits animal experiments if there really are no alternatives available for the research in question. If an animal experiment is really necessary, the directive sets rules on the quality of the animals’ housing and their care. The ultimate goal is to completely replace animal experiments with alternative research methods as soon as possible, and the European directive is an important step in that direction.
The Netherlands has the Experiments on Animals Act (Wod) (website in Dutch). This act was revised (website in Dutch) on 18 December 2014 to follow the European directive. In some cases, the Experiments on Animals Act is stricter than the European directive. As a result, the Netherlands offer a relatively high level of protection laboratory animals.
The objectives of the Wod are:
To improve the protection of animals used for research.
To apply the 3Rs (Replacement, Reduction and Refinement) to the treatment and use of animals used for research.
To restore a level playing field for commercial and scientific research in the European Union.
The Wod applies:
To animals used for scientific, regulatory or educational purposes or intended to be used for such a purpose, or to animals bred specifically so that their organs or tissues can be used for scientific or educational purposes.
Until the animals are either killed or adopted, or until they have been returned to their natural habitat or a suitable ‘husbandry system’.
To living non-human vertebrates and live cephalopods (octopuses and squids).
To living foetal forms of mammals from the last third of their normal development, and also to independently feeding larvae.
One of the most important tasks of the NCad is to create visible changes for Replacing, Reducing and Refining (3Rs) in animal testing. We do this by sharing knowledge about the 3Rs and ethical permissibility of animal testing. In this way NCad contributes to accelerating the development of animal-friendly alternatives and minimizing the use of laboratory animals. Below you can find more information.
Animal experiments must be replaced by alternatives wherever possible. Although the replacement of animal experiments is currently not always possible, there are various alternative models and methods available, such as:
Cultured cells and tissues
Human or animal material
Human volunteers
DNA techniques
Computer models and AI.
The government encourages the development of new research methods that do not require laboratory animals, for example through the Transition to Non-animal Innovations programme. More examples of non-animal methods can be found on the programme’s website. We provide advice to parties who wish to replace animal experiments with non-animal alternatives. For example, in 2023 we published an advisory report on the availability and accessibility of human tissue.
If animal experiments cannot be avoided, then in any case as few animals as possible must be used. This could be achieved by using different measurement techniques, or a better-designed model, for example. Ways of reducing animal experiments should be considered right from the start, with the design of the experiment. The researcher is responsible and must be able to clearly justify the number of animals used. We can help researchers to make these reductions, for example by providing advice on how to conduct a preliminary study for a project licence application.
Some studies require genetically modified animals to be bred. These animals may be required to find out how genes affect inherited diseases. Breeding animals with a specific combination of genes often requires many additional animals that are not used for the research. These may be parent animals that have been used for breeding, or offspring that does not have the right combination of genes. In animal research the term ‘killed in stock’ is used to describe animals that are not used for the experiment but will be killed. In our advisory report on breeding laboratory animals, we describe how to reduce the number of ‘killed in stock’ animals. An important advice in this report is to require the appointment of breeding coordinators to monitor the quality and application of techniques, methods and breeding schedules.
It is important to reduce suffering (pain, fear, distress, etc.) in laboratory animals as much as possible during an animal experiment. This can be aided by providing suitable housing implementing training programmes, habituation periods, less painful measurement techniques, and adequate pain management. It is important to apply refinement throughout an animal’s life; i.e. not only during the experiment, but also during the breeding phase and prior to/after the trial.
Refinement can be achieved by:
Improving and adapting housing as much as possible to specific animal species (because a mouse has other needs than a dog).
Housing social animals (such as rats and mice) together in a cage and providing sufficient materials for play and environmental enrichment. Providing materials that are specific to a species will allow the animals to exhibit more natural behaviour.
Training the animals to prepare them for certain interventions, such as blood sampling (as is the case with dogs and apes in the Netherlands).
