Facts and figures 2015

Number of animals used for scientific purposes at the MDC

Animal species at the MDC

MDC scientists use mainly mice and rats for their research. The close evolutionary relationship between these animals and humans makes them highly valuable for research into human diseases.

Other species are also important in the institute's research, at lower numbers. While animals such as zebrafish or clawed frogs (Xenopus) bear less similarity to humans, they have other advantages for experimental work. They lay eggs, for example, making it much easier to study the way their embryos develop than in species where the early stages of life take place inside a mother's body.   

Approximately half of the number of rodents (mice and rats) and most of the fish have undergone genetic modifications. These animals are immensely important in helping scientists understand the connections between genes and states of health and disease, an essential step in designing treatments.

Type of experiments

Most of the animals reported by the MDC were eventually sacrificed to provide scientists with samples of cells or tissues that couldn't be obtained in any other way. These animals appear in the category "non-recovery", which also also includes the number of animals that died while placed under anesthesia for a procedure.

In many other types of experiments, animals suffer only mildly. A small number of experiments involve severe suffering; here the animals are treated with analgesics and other measures are taken to ease their distress. Everyone regards this situation as an unfortunate necessity, a trade-off which balances the animals' distress against the potential for meaningful gains in medical or scientific knowledge. At every stage, scientists pursue the principle of the "three Rs" (reduce, refine, replace): the aim is to keep the number of animals as low as possible, to use alternative methods whenever possible, and to minimize pain and suffering to the best of their ability. Read more about this here.

Severity categories according to EU Directive 2010/63/EU

on the protection of animals used for scientific purposes

Full text of EU Directive 2010/63/EU (PDF)

  • Non-recovery:
    Procedures which are performed entirely under general anaesthesia from which the animal shall not recover consciousness.
  • Mild:
    Procedures on animals as a result of which the animals are likely to experience short-term mild pain, suffering or distress, as well as procedures with no significant impairment of the well-being or general condition of the animals.
  • Moderate:
    Procedures on animals as a result of which the animals are likely to experience short-term moderate pain, suffering or distress, or long-lasting mild pain, suffering or distress as well as procedures that are likely to cause moderate impairment of the well-being or general condition of the animals.
  • Severe:
    Procedures on animals as a result of which the animals are likely to experience severe pain, suffering or distress, or long-lasting moderate pain, suffering or distress as well as procedures, that are likely to cause severe impairment of the well-being or general condition of the animals.