Reflections on improved health status of rodents bred for research: contributions to the reduction and refinement of animal use.

Reductions and refinements in the use of animals have steadily occurred over the last century. The need for improved health status has been a catalyst for much of this effort. This has also driven improvements in the housing and husbandry techniques required to maintain the health status of animals produced or used for biomedical research. This has decreased the number of animals used in biomedical research studies, contributed to refinements in animal care and use, and has resulted in better science as well as better animal welfare. 2009 FRAME.