The Three Rs principle was launched in the early 1960s by two English
biologists, Russel and Burch in their book “The Principle of Humane Experimental
Technique”. The 3 Rs stand for Replacement, Reduction and Refinement.
Replacement alternatives refer to methods which avoid or
replace the use of animals. This includes both absolute replacements (i.e.
replacing animals by computer models) and relative replacements (i.e. replacing
vertebrates, with animals having a lower potential for pain perception, such as
Reduction alternatives refer to any strategy that will result
in fewer animals being used to obtain sufficient data to answer the research
question, or in maximizing the information obtained per animal and thus
potentially limiting or avoiding the subsequent use of additional animals,
without compromising animal welfare.
Refinement alternatives refer to the modification of
husbandry or experimental procedures to minimize pain and distress, and to
enhance the welfare of an animal used in science from the time it is born until