Scientific uses of animals: harm-benefit analysis and complementary approaches to implementing the three Rs.

The principles of humane experimental technique, first described by Russell and Burch in 1959, focus on minimising suffering to animals used for scientific purposes. Internationally, as these principles became embedded in the various systems of oversight for the use of animals in science, attention focused on how to minimise pain, distress and lasting harm to animals while maximising the benefits to be obtained from the work. Suffering can arise from the experimental procedures, but it can also arise from the manner in which the animals are housed and cared for. Increased attention is therefore being paid to the entire lifetime experience of an animal, in order to afford it as good a quality of life as possible. Russell and Burch were also concerned that animals should not be used if alternatives to such use were available, and that animals were not wasted through poor-quality science. This concept is being revisited through new efforts to ensure that experiments are well designed and properly reported in the literature, that all results--positive, negative or neutral--are made available to ensure a complete research record, and that animal models are properly evaluated through periodic systematic reviews. These efforts should ensure that animal use is truly reduced as far as possible and that the benefits derived through the use of animals truly outweigh the harms.