Scientific research projects involving animals are required to undergo ethical evaluation to ensure that they address important ethical concerns related to animal welfare and the scientific quality of the research before they are approved. Researchers continue to propose tools to aid decision-making; however, the extent to which such resources are currently available, their jurisdictions of applicability and how they guide decision-making are not entirely clear. A Scoping Review from sources of evidence systematically collected in PubMed, Scopus, and Web of Science from 1985 to 2023. 17 resources that can guide ethical decision-making were identified. These sources discussed what should constitute harm to animals and the benefits of research and how these two interests can be balanced to make a decision. Some adopt mathematical calculations, some propose guidelines for committee discussions, while others propose the combination of different approaches to decision-making. In conclusion, more deliberations among committee members should be supported over scoring approaches. Additionally, making ethical decisions on a case-by-case basis should be more desirable than accuracy, which may not be plausible.