A practical framework for refining experimental procedures

A practical approach to identifying and minimising the incidence and extent of the adverse effects caused by scientific procedures on the experimental animal is set out. Severity is defined as adverse impact on animal welfare in terms of pain, suffering. distress and lasting harm. Refinement to minimise severity tin extent and duration) can be achieved by re-engineering the experimental protocol or by incremental improvements. In practice, refinement can be divided into three phases: before the experiment starts (making predictions and setting standards); during the experiment (observation and recording); and after the experiment (comparison and action). However. the design of the protocol is an iterative process, and once implemented it requires regular review to incorporate external information and experience, to achieve further refinement over time. This paper illustrates the advantages of having a structured approach to refinement.