The extended welfare assessment grid: a matrix for the assessment of welfare and cumulative suffering in experimental animals.

Combining a range of assessment parameters into one usable entity has been identified as an important goal in providing a practical, objective and robust assessment of welfare, particularly in laboratory animals. This paper refines and extends one such previously published method. The proposed Extended Welfare Assessment Grid provides for the incorporation of changes in the state of an animal over time, allowing for predictive, retrospective, scheduled, or event monitoring. It enables the numeric, as well as visual, representation of the animal's welfare, placing this in the context of the careful and realistic justification for experimental use of the animal. This assessment method represents a valuable tool for those tasked with ensuring ethical oversight, as well as for those planning the use, or monitoring, of animals in research. It is particularly applicable to animals used in long-term studies, especially non-human primates. It is believed that this system will draw attention to the temporal component of suffering that is often overlooked in the planning of research schedules and allow an assessment of cumulative suffering imposed by the events that occur.