The welfare of non-human primates used in scientific research must be safeguarded to promote scientific validity and for ethical reasons. Welfare can be improved by the refinement of practice, particularly if these refinements are applied to every aspect of the life of an animal used in the laboratory, from birth to death with the aim of both minimising harm and maximising well-being. Many refinement methods have been described in nationally and internationally accepted guidelines on laboratory practice, but awareness of these guidelines is not universal. In Part I of this review, we examine the influence of humans on non-human primates and summarise and evaluate methods of refinement that are or could be used to reduce suffering and improve welfare. In particular we focus on staff selection, education and training, human–animal bonds, staff communication, and training primates. In Parts II and III, refinements of housing, husbandry and experimental procedures are reviewed.
