Question to the Home Office:

To ask His Majesty's Government, with regard to the Animals in Science Regulation Unit Annual Report 2024, published in December 2025, what assessment they have made of the incident in which 26 mice were found to have drowned when their cage flooded overnight due to a leaking water valve; whether they have considered the adequacy of a 'letter of reprimand' being issued as a sanction in response; and what actions they will be taking to prevent animals who are being kept for the purpose of scientific experiments from drowning in future.

All licensed establishments must fully uphold the required standards for animal welfare as set out in the Animals (Scientific Procedures) Act 1986 (ASPA) and the Code of Practice for the Housing and Care of Animals Bred, Supplied or Used for Scientific Purposes. The Animals in Science Regulation Unit (ASRU) conducts audits to assure establishments’ compliance and takes matters of non-compliance very seriously.

Regarding the incidents referenced, ASRU investigated the incidents and acted according to the published compliance framework (www.gov.uk/guidance/animal-testing-and-research-compliance-with-aspa) which explains how ASRU identifies and investigates potential incidents of non-compliance and decides on appropriate and proportionate measures and remedies where non-compliance has been found to occur. Through delivery of the compliance policy the Regulator aims to reduce the risk of future non-compliance.

All cases of non-compliance are thoroughly investigated, and the outcomes are published in ASRU’s annual report.