Experimental animals used by the MPI-CBG and registered with the authorities in 2019 can be seen in the pie chart. The most frequently used experimental model in 2019 was mouse (82%) followed by zebrafish (16%). In 2019, the majority of procedures carried out were categorized as being mild (78%); the proportion of moderate procedures was 3%. We do not carry out any procedures categorized as severe. The proportion of ‘non-survival’ procedures carried out under general anesthesia and the proportion of animals used for organ and tissue collection after humane and painless euthanasia, was 18%. Experimental animals which have been painlessly euthanized for the collection of biological materials (e.g. cells, tissues and organs) have not been subjected to any other form of stress or procedure. Although the majority of our experiments cause either no pain or only mild pain, if a procedure has the potential to cause suffering and/or pain, we are committed to keep this as low as possible by monitoring their well-being daily (or constantly if needed), using pre-defined scoresheets to evaluate humane endpoints, as well as applying analgesics and other measures (e.g. stress-free environment, gentle handling) to ease distress.

The types of experiments according to severity categories are defined by EU Directive 2010/63/EU (PDF link: https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:276:0033:0079:en:PDF). Definitions are shortly summarized below:

Non-recovery:
Procedures which are performed entirely under general anesthesia from which the animal shall not recover consciousness. Includes animals euthanized painlessly to obtain cells or tissues for cell culture (no experiments performed).

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. Typical examples may be a single injection or removal of a small tissue sample for genotyping purposes.

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. Typical examples are simple survival surgeries such as introducing an imaging window for microscopy.

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. We have never performed a procedure within this category.