How much do animals suffer during experiments?
There are different types of experiments in which the animals’ well-being is affected to a greater or lesser extent. While drawing blood causes only minor pain, an operation in which, for example, nerves are cut to study the effects of muscle atrophy can cause more severe and longer-lasting pain or impairment.
Anyone wishing to carry out an animal experiment must, in addition to the legally required training and approval, assess and document – before, during and after the experiment – how the stress on the animals is to be classified.
“Stress” refers to the pain, suffering, distress and lasting harm that an animal experiences, and the classification of procedures considers the measures with which this can be minimized.
The European Union Directive 2010/63/EU “On the protection of animals used for scientific purposes” (LINK) distinguishes between four categories of procedures:
- Mild: Animal procedures in which animals are subjected to brief and minor pain, suffering or harm, such as a single blood withdrawal or injection. These are procedures that are also routine in a veterinary practice.
- Moderate: Animal experiments in which animals are subjected to short periods of moderate pain, suffering or harm, or longer periods of minor pain, for example, during surgical procedures under general anesthesia followed by drug treatment for pain.
- Severe: Animal experiments that cause severe pain, suffering or harm to an animal or prolonged moderate pain, suffering or harm that could result in the death of the animal.
- Non-recovery: Animal experiments in which animals that have not previously undergone any procedures are killed for scientific purposes – for example, to remove individual organs; or experiments in which animals are placed under general anesthesia (to undergo minor surgery), and are then euthanized while still unconscious.
The German Federal Institute for Risk Assessment (LINK) regularly surveys how many laboratory animals are exposed to which degree of stress.