Animal testing and research dates back to the writings of the Greeks in the 4th and 3rd centuries BC, with Aristotle and Erasistratus among the first to perform experiments on living animals. Avenzoar, an Arabic physician in 12th-century Moorish Spain who practiced dissection, introduced animal testing as an experimental method of testing surgical procedures before applying them to human patients.
As animal experimentation and dissection continued, opposition to it grew. First recorded in the seventeenth century, those against vivisection argued that an animal’s physiology could be affected by the pain caused during an experiment, therefore rendering the results unreliable. Others saw animals as inferior to humans and so different that results from animals could not be applied to humans.
In 1954, Charles Hume, founder of the Universities Federation for Animal Welfare (UFAW) in the UK made an original proposal to UFAW to take into consideration alternatives for animal testing and change scientific study in laboratory animal experiments.
The microbiologist Burch and the zoologist Russell were chosen to further develop the Hume’s proposal. "The Principles of Humane Experimental Technique" was published in London in 1959, and the book defined animal testing alternatives as “The Three R's: Refinement, Reduction, and Replacement.”
- Replacement refers to the preferred use of non-animal methods over animal methods whenever it is possible to achieve the same scientific aim.
- Reduction refers to methods that enable researchers to obtain comparable levels of information from fewer animals, or to obtain more information from the same number of animals.
- Refinement refers to methods that alleviate or minimize potential pain, suffering or distress, and enhance animal welfare for the animals still used.
Over the past 40 years the 3Rs have become widely accepted ethical principles, and are now embedded in the legislation and conduct of animal-based science.
Before any research can be performed, an independent panel must consider whether animals are required or whether suitable replacement alternatives exist. When animals are used, the investigator must consider how best to decrease the number of animals used to a minimum and/or how to maximize the amount of information obtained per animal (Reduction alternatives), and must identify potential harms and ways to minimize these (Refinement alternatives).