Transparency in animal research enables public scrutiny, facilitates scientific progress and supports welfare improvement. Understanding the current state of transparency and its gaps informs advocacy.
Transparency in animal research is a welfare issue because hidden animal use cannot be scrutinised for 3Rs compliance or welfare standard adherence. When experiments are not published, the suffering of animals used contributes nothing to scientific knowledge and may be duplicated by other researchers. When methods are not fully reported, other scientists cannot evaluate whether 3Rs were adequately implemented. Mandatory pre-registration of animal studies, similar to clinical trial registration, would reduce duplication, improve methodology and make welfare reporting part of the public record. The cultural shift required is from treating animal research as proprietary to treating it as a public trust that requires accountability for the welfare costs incurred in public benefit research.