Even beyond animal testing: possibilities for an overall assessment of animal well-being

Abstract

Abstract Background The concept of well-being encompasses the physical and mental/emotional health of an individual. For animals, well-being is often defined merely by the absence of pain, suffering, fear, stress, or harm, and is generally difficult to assess for individuals who cannot communicate for themselves. In laboratory animal science, severity assessments have been mandatory by law since 2013, whereby stressors are initially considered as the sum of all factors leading to deviations in the well-being of animals. Depending on the interventions and treatments conducted, corresponding severity levels are then defined. Assessments of severity must occur before, during and after the experiment, with corresponding ethical considerations being made. Various severity assessments have been created for a large number of individual manipulations. However, when multiple harmful interventions or stressors occur simultaneously, the cumulative overall severity cannot be captured objectively, often leading to significant underestimation. Methods A comprehensive analysis was conducted on 20 legally mandated records of animal experiments (approval authorities in Germany: Regierungspräsidium Gießen and Freie Hansestadt Bremen) from the years 2015–2023. This analysis involved daily examination of the effects of each experiment on the respective animals or groups of animals. The aim was to identify significant stressors across various research domains. Results In order to visualise these cumulative occurring stressors, a scoring system was developed to estimate the overall stress loads within the context of an animal experiment and outside of animal experiments. The developed scoring system is based on four different aspects, namely the definition of the [1] highest individual stress load, the assessment of [2] parallel and [3] serial individual stress loads and the consideration of a [4] baseline load. From these four different aspects, a cumulative overall stress load can then be determined through point allocation. Discussion This scoring system is highly effective in objectively depicting cumulative stress load and covert burden. It is crucial that it is optimized for the respective situation and that care is taken to ensure that the point allocation is coherent and tailored to the specific testing project or situation.