Russell and Burch’s 1959 original definitions of the 3Rs (replacement, reduction and refinement) are widely used today as standards for the ethical use of non-human animals in research, although they have a number of limitations. Authors and institutions around the world have addressed some of these, coming up in certain cases with more accurate, functional, and up-to-date definitions. However, not only do there still remain limitations needing to be addressed, but some that have been addressed resulted in discrepancies, contradictions, and general confusion as to how best apply the 3Rs in practice. In order to clarify the meaning of the 3Rs and enable more optimal implementation of these principles in animal experimentation, this article provides a theoretical discussion for revised definitions of the original 3Rs via examination of some of their main limitations and inconsistencies. First, we offer up the original definitions as presented in the context of Russell and Burch’s book The Principles of Humane Experimental Technique. Then, we examine the main limitations and present clear specifications and requirements for such revised definitions. After presenting our revised definitions, we conclude with various implications for animal welfare within the context of experimentation.

Objectives: The purpose of this systematic review was to examine how the scientific community in Europe that is involved with research with animals perceives and experiences the implementation of 3R (Replace, Reduce, Refine).Methods: A systematic search of the literature published in the past ten years was performed in PubMed, Web of Science and Scopus. Publications were screened for eligibility usinga prioriinclusion criteria, and only empirical evidence (quantitative, qualitative, or mixed methodologies) was retained. Quantitative survey items were investigated by conducting a meta-analysis, and the qualitative data was summarized using an inductive meta-synthetic approach. Included publications were assessed using the Quality Assessment for Diverse Studies tool.Results: 17 publications were included (eight quantitative, seven qualitative, two mixed-methods). The meta-analysis revealed that scientists are skeptical about achieving replacement, even if they believe that 3R improve the quality of experimental results. They are optimistic concerning the impact of 3R on research costs and innovation, and see education as highly valuable for the implementation of 3R. The meta-synthesis revealed four barriers (systemic dynamics, reification process, practical issues, insufficient knowledge) and four facilitators (efficient use of animals, caring for animals, regulatory uptake, supportive workplace environment).Conclusion: These findings show actionable levers at the local and systemic levels, and may inform regulators and institutions in their 3R policies.Trial registration: The protocol was registered into the PROSPERO database under the numberCRD42023395769.

Changing relationships with nonhuman animals have led to important modifications in animal welfare legislations, including the protection of animal life. However, animal research regulations are largely based on welfarist assumptions, neglecting the idea that death can constitute a harm to animals. In this article, four different cases of killing animals in research contexts are identified and discussed against the background of philosophical, societal, and scientific-practical discourses: 1. Animals killed during experimentation, 2. Animals killed before research, 3. “Surplus” animals and 4. “Leftover” animals. The scientific community and, accordingly, animal research regulations such as the internationally acknowledged framework 3R (“Replace”, “Reduce”, “Refine”) tend to aim at the reduction of “surplus” and, to some extent, “leftover” animals, whereas the first two classes are rather neglected. However, the perspective that animal death matters morally is supported by both societal moral intuitions and certain theoretical accounts in animal ethics. Therefore, we suggest the implementation of the 3Rs in regulations, so that they: 1. Make their underlying philosophical position transparent; 2. Are based on a weighing account of animal death; 3. Are applicable to procedures on living and dead animals; 4. Apply the “reduction” principle to procedures on dead animals; 5. Entail that methods using (parts of) dead animals need to be replaced by animal free methods, if possible; 6. Do not suggest replacing research on living animals by research on killed animals; 7. Include all kinds of animals, depending on the respective harm of death; 8. Are applied to the broader context of experimentation, including breeding and the fate of the animals after the experiment.

This report is a result of an interdisciplinary workshop held at the Collegium Helveticum in Zurich, Switzerland in February 2024, in which ideas for accelerating NAMs (New Approach Methodologies) in Swiss universities were shared and discussed. Due to regional differences in university organisation and funding structures, not all recommendations will be transferable to all regions worldwide. All participants were qualified to contribute to the discussion, due to their knowledge and experience of the Three Rs, in particular with regard to their implementation. The workshop participants believed that universities, which play a pioneering role in so many other areas, should also exploit their innovative potential in the field of animal-free research. The workshop uncovered four areas that would need to be addressed in order to achieve a significant change in university science culture and do more justice to the Three Rs, namely: language — innovative framing (pro-replacement framing in official university statements); knowledge transfer — communicating innovative findings in teaching (redirecting curriculum); change of values within science faculties; and structured implementation and well-coordinated planning of the transformation (establishment of a ‘transition unit’). Specific strategies for implementing these four areas are outlined. In addition, we discuss why the replacement of animal testing should be an essential goal for universities, why this goal has not yet been achieved, and why concerted efforts toward change are required.

The use of animal cadavers in initial and continuing veterinary education is widely accepted, but ethical considerations regarding how to obtain and use them are often lacking. It can be argued that the use of animal cadavers should be guided by principles similar to those regulating the collection of human cadavers for scientific purposes. In humans, the use of unclaimed cadavers from unknown provenance, cadavers from criminals or homeless people, or cadavers robbed from their grave no longer happens in most countries. Accordingly, body donation programs have been emphasized to be the sole acceptable source of cadavers for medical education. The purpose of this article is to argue that this should also be the case for domestic animals, contrary to the current practices of using unwanted animals or animals bred for this purpose. But having a body donation program is not enough to make it ethical: care should also be taken in order to include principles such as informed consent from the owners, the absence of commercial uses of the bodily remains and the respect for all parties involved in the process. Overall, the importance of maintaining respect towards the reception and use of a donated cadaver in all circumstances should be the ethical priority for students and practitioners. By applying such principles, we can better ensure that the use of animal cadavers in education and training is transparent, respectful and responsible.

Animal breeding is a mainstay of our relationship with domesticated species. However, it is sometimes leading to serious health and welfare issues, such as canine brachycephaly or double-muscling phenotype in Belgian Blue cattle. How then can we re-think our breeding system in animals? In this paper, I discuss the ethics of domestic animal breeding and new ways to achieve it. In doing so, I focus primarily on the concept of eugenics and its two major accounts: authoritarian and liberal eugenics. Indeed, the debates surrounding eugenics in humans is a quite prolific framework to question how we can justify animal breeding and has the merits to clarify the conditions needed to consider some practices as morally wrong (e.g. in the case of authoritarian eugenics). I argue that pure-bred breeding is comparable in many ways with authoritarian eugenics primarily because it does not consider the benefits for the animals but external factors such as beauty, productivity or certain behaviors. But arguing so raises the question whether this renders all types of animal breeding unethical. I refute this conclusion and give some arguments to support an active use of more ethical kinds of breeding systems. Specifically, I explore the concept of liberal eugenics and its limitations to defend a breeding practice that is both liberal and responsible. Such new standards can warrant a focus on animal welfare and put forward the central role of breeders in this process.