Animals used in scientific research may survive beyond procedures or be surplus to breeding programmes, raising questions about post-study outcomes. Rehoming, defined as the transfer of animals bred for or used in research into a living situation outside experimental use, can be an alternative post-research outcome where animals would otherwise be killed. We conducted a scoping review of peer-reviewed literature on policies, guidelines, and recommendations for rehoming animals used in research settings. The review was conducted in accordance with Joanna Briggs Institute (JBI) guidance and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). We searched four databases and included fifteen papers. Across the reviewed literature, rehoming is predominantly positioned as a legally permissive and conditional post-research option rather than a mandatory requirement. We identified three governance levels: regulatory frameworks set conditions; professional and practitioner associations translate these into guidance; and individual institutions implement local policies and programmes. Two main rehoming models were described: adoption-based and retirement-based, each with distinct responsibilities and resource demands. Barriers included limited time, funding, infrastructure, liability, and difficulties identifying suitable adopters, while facilitators included dedicated staff roles, institutional experience, external partnerships, and budgeting rehoming costs within research grants. Species-specific restrictions were also reported, including legal and biosecurity rules that affect rehoming eligibility. Ethical justification was based on the concepts of animal welfare, alongside responsibility and justice. In conclusion, rehoming is generally optional and varies with local capacity and infrastructure, with some papers noting limits on post-transfer follow-up and eligibility exclusions. This may affect animal welfare by making post-research outcomes less consistent and by limiting support after transfer.
