Animal welfare

We carry a profound responsibility for our research animals and strive to provide them with the best possible quality of life. In our studies, we make every effort to avoid and minimise discomfort for the animals. Below, you can learn more about how this is put into practice.

The well-being of laboratory animals is a collective responsibility

Ensuring the welfare of animals is a task for everyone: from the Animal Welfare Body (AWB) to managers, from researchers to animal caretakers. The AWB Leiden devotes significant attention to creating and fostering a culture in which we collectively assume responsibility for the best possible care and treatment of our laboratory animals – a culture of care. We strive to provide the best care for all animals and aim to minimise any discomfort they may experience. Moreover, there is open space for all colleagues to discuss their work, express concerns, and consistently contemplate how we can further improve our research involving animals.

In this way, the AWB Leiden ensures that all animal experiments at Leiden University are conducted responsibly. We prioritise animal welfare and uphold high standards for the quality of our research.

The care of research animals

Only certified animal caretakers are responsible for the care of the animals. All caretakers and biotechnicians have completed a three- or four-year training programme, enabling them to provide optimal care for the animals. The animal caretakers also hold an additional certification for working with research animals, known as the Article 13f2 certificate. Some caretakers have undergone additional training or specialisation to perform a limited number of biotechnical procedures, such as injections, collecting blood samples, or marking animals.

On a daily basis, caretakers check if all animals have sufficient water and food and ensure they are lively and healthy. This routine extends to weekends and holidays. Due to their experience and expertise, caretakers can quickly identify abnormal behaviour. They document their findings in welfare journals.

Animal welfare: discomfort and pain

In animal experiments, some form of discomfort is always present. This doesn’t necessarily mean that animals are in pain; discomfort refers to any reduction in well-being.

This may indeed involve pain, but it can also include stress or anxiety. When designing an experiment, we make every effort to minimise this discomfort. This can involve measures such as pain management or performing procedures under anesthesia to ensure the animal experiences as little distress as possible. In most of our studies, animals experience mild discomfort (approximately 90%), about 8% involve moderate discomfort, and in rare cases (less than 1%), there is severe discomfort. You can find the exact figures on our page Facts and Figures on Animal Experiments.

Mild discomfort might include needle insertion, a brief sedation, or a few days of solitary confinement in a cage. Moderate discomfort could involve surgery, undergoing various injections, or a longer period of solitary confinement. Severe discomfort implies that an animal experiences moderate discomfort for an extended period.

What happens after an animal experiment?

Most research animals are euthanised after the conclusion of an animal experiment. This decision depends on the research question the investigator aims to answer and the requirements for that purpose. For instance, if organs are needed, the animal cannot continue to live afterward. There are also other reasons why a research animal might be euthanised, such as the inability to guarantee long-term welfare or if the animal is genetically modified. Genetically modified animals are not allowed to be housed elsewhere.

In rare cases, it may be possible to offer animals for adoption. This is, for example, applicable to animals used solely for breeding, primarily involving zebra finches. During the adoption process, all animals are examined by a veterinarian, and we ensure that the new owner has adequate knowledge and attention to care for these former research animals.