Harmful and non-harmful phenotypes of mice

The article 4.3 of the Directive 2010/63 states that “Member States shall ensure refinement of breeding, accommodation and care, and of methods used in procedures, eliminating or reducing to the minimum any possible pain, suffering, distress or lasting harm to the animals”. Based on definition, it is is crucial to reach consensus on what should be assessed as harmful. This Working Group is established to define the most updated and consensus-based approaches to assess the welfare of genetically altered mice as well as the wild-type line with corresponding genetic background. Further, the WG the will provide guidance on how to compare statistically the burden of wild-type and genetically altered lines.