Severity degrees of animal experiments

During an experiment, animals are exposed to various degrees of distress caused by interventions and measures. These stresses are divided into four different categories known as severity degrees. This classification is Download published (PDF, 710 KB) by the Federal Food Safety and Veterinary Office (external page FSVO ) and applied by the authorising cantonal veterinary offices.

When assessing the degree of animal suffering, the cumulative effect is also taken into account if several interventions and measures are carried out on the same animal.

No pain, injury or stress and no impairment of their general state of health.

Examples:

Observational studies in behavioural biology
Collection of cells, organs or bodily fluids from dead animals
Food deprivation, e.g. overnight with subsequent compensatory possibilities

Minor and short-term pain, injury or stress and impairment of their general state of health.

Examples:

Repeated injection of small volumes
Subcutaneous injection of tumour tissue
Skin tissue biopsy

Short-term moderate or minor medium- or long-term pain, injury or stress and impairment of their general state of health.

Examples:

Repeated blood sampling over several days,
Overweight mouse with diabetes
Surgical procedure to open the animal��s abdominal cavity

Medium- or long-term moderate to severe pain, injury or stress and impairment of their general state of health.

Examples:

Organ transplantation
Animal models with aggressive cancer
Immune cell transfer to induce intestinal inflammation