THE THREE Rs

The use of animals in research, teaching and testing is not a right but a privilege. It is incumbent upon every researcher to ensure that privilege is not abused. Even though animals are, in most cases, bred for research, that does not mean that we may use as many as we like in whatever way we like. Each animal is an individual and should be treated as such. We must be careful that they are not subjected to needless pain or suffering. Excessive numbers should not be used just because they are there. They should not be used at all if an equally suitable model system could be used to obtain the same results. Every possible step must be taken to reduce or prevent pain and suffering.

By evaluating each research, teaching or testing protocol for adherence to the principles of the Three Rs, we will replace, reduce and refine the use of animals in science.

THE PRINCIPLES OF HUMANE EXPERIMENTAL TECHNIQUES

The question of pain and distress in animals used for research, teaching and testing has concerned the general public and thoughtful researchers for a long time. It was this concern, together with increasing use of animals in fundamental and applied research that motivated W.M.S. Russell and R.L. Burch to examine how decisions should be made about such use of animals.

The Three Rs stand for Reduction, Replacement and Refinement. In the book The Principles of Humane Experimental Technique, published in 1959, the authors Russell and Burch proposed that all research using animals should be evaluated to see if the Three Rs could be applied. They recognised that while the replacement of animals as research subjects was a desirable goal, considerable gains could be made in humane science through reducing the numbers of animals used and by refining the techniques that were applied to animals. Over the past 40 years the Three Rs have become widely accepted ethical principles to be embedded in the conduct of animal based science.

The word "alternatives" came into use after 1978 following the publication by David Smyth, a physiologist and President of the UK Research Defence Society, of Alternatives to Animal Experiments. In this book, Smyth provided a Three Rs definition of alternatives: “ All procedures which can completely replace the need for animal experiments, reduce the numbers of animals required, or diminish the amount of pain or distress suffered by animals in meeting the essential needs of man and other animals."

THE THREE Rs AT A GLANCE

As has been noted, the word alternatives is used to describe any change from present procedures that will result in the replacement of animals, a reduction in the numbers used or a refinement of techniques that may reduce or replace animals or reduce the pain, stress or distress of the animals.

REPLACEMENT of animals (all living vertebrates except humans) in research with alternative techniques, lower species, or avoiding animal use altogether.

REFINEMENT of scientific procedures to minimize animal suffering, enhancing welfare throughout their lives in the animal house, as well as in research situations.

REDUCTION of the number of animals used by obtaining more information from the same number of animals, or the same amount of information from fewer animals.

REPLACEMENT

Non-animal research techniques have helped to reduce the number of situations in which animal procedures are needed. These techniques include the use of statistical data already obtained from animal research, studies of isolate cells and tissue, new scanning methods, computer models that simulate an animal’s response to specific experiments, and studies of patients and populations.

Much safety testing can now be undertaken without the use of animals. For example, the Ames test uses bacteria instead of rodents to see whether a chemical is likely to damage DNA or has potential to cause cancer. Similarly, some test now use less complex animals than before: scientist can test injected medicines for most fever-causing bacterial contaminants, by using blood cells from the horseshoe crab – replacing test on rabbits.

REFINEMENT

Refinement is about improving animal welfare and reducing any potential pain or suffering. Simply improving housing and care in research – often through ‘’environmental enrichment’’ – means animals live better lives with less stress.

There are many specific refinement techniques and they apply to almost all aspects of an animal’s life. For example, food rewards can be used to train monkeys to sit on weighing scales, or hold out a limb to give a blood sample – reducing stress. Blood pressure, heart rate and activity levels can be measured by radio-operated implants, so that the animals do not have to be repeatedly caught or restrained. Rodents can be housed in a special red plastic ‘’house’’ in order for them to feel they’re nesting a dark place (they can’t see through red), yet it allows them to be seen and studied. And, of course, animals are routinely kept in social groups and given stimulating environments.

REDUCTION

Reduction refers to using fewer animals to obtain the same - or more – research information.

This can be achieved in many ways. Good experimental design and statistical analysis ensure that researchers use the optimum number of animals. Using inbred animals means researchers can obtain reliable results from fewer animals. New scanning techniques mean that tumors can be tracked non-invasively, with more data collected from the same animal. And measures such as freezing embryos mean that fewer rodents are needed for genetic modification breeding programmes – they can be implanted when needed.

Despite these positive changes, thousands of animals are still used every year. Clearly there is still much to be done. The Research Ethics Unit will strive to ensure that all research animals have a voice, and that every step is taken to reduce suffering and improving their welfare.

Page inserted: 22/03/2010