Do animals always suffer in experiments?
No, according to statistics, most animal experiments place little or no constraint on the animals. It depends on the research question and the methods used whether an animal is stressed in an experiment or not. There are many experiments in which the animals do not suffer, or the husbandry and handling do not differ from that outside an experiment.
Most feeding studies (i.e. testing a feed for animals), for example, are not stressful for the animals. Nevertheless, the persons carrying out the experiments need a license from the competent authority. If an improved X-ray method is scientifically investigated in animals, which would undergo that procedure anyway, this does constitute an animal experiment requiring authorisation, but the animal is not subjected to any additional stress through the study.
Of course, researchers carry out experiments in which animals can suffer. These are necessary and required, for example, to assess the toxicity of an active substance and test the safety to humans. And in basic research animal experiments with higher degrees of severity are conducted for example to study diseases such as multiple sclerosis, infections or tumours.
Some research questions require that animals must be made sick. In some animal experiments, it may sometimes be possible to induce a disease only to a small extent to assess the effect of a drug. When studying a cancer drug, it is often enough to show that it can inhibit the tumour in its development. Here, imaging techniques may also help to detect even the smallest changes, such as tumours or metastases, at which point the study can be ended before the animals suffer too much.
When planning the experiment every researcher must consider when to stop the experiment and how to do it so that the animals suffer as little as possible. These humane endpoints are considered when the competent authorities issue an authorisation for an experiment.
How often are constraining animal experiments carried out in Switzerland?
The proportion of animal experiments in Switzerland that are classified as resulting in moderate or severe constraint on the animals varies from year to year. Usually about a quarter of all experiments are classified as distressful; about three percent of all animals on which animal experiments are carried out are exposed to severe constraint. Most of these experiments are carried out on mice or rats. The Federal Veterinary Office publishes detailed information on approved animal experiments in the animal experiment statistics.
