Use of animals in experimental research: a scientist's perspective.

The present article was written as an attempt to understand the position of animal rights groups, to stimulate scientists to define their own positions, and to encourage scientists to interpret their use of animals to the rest of society. The article attempts to generate a statement of practices that might be useful in experiments that utilize animals in research. The statement is an extension of the three R's originally proposed by Russell and Burch (W.M.S. Russell and R.L. Burch [1959]: Principles of Humane Experimental Technique, Springfield, IL, Charles C. Thomas) into four R's: refinement, reduction, replacement, and review.