Throughout the past century, animal testing has had a critical role in advancing medical research, hence providing an improved quality of life and wellbeing. Despite this, the issue of animal testing is a very topical one with many ethical issues associated with it.
Our society would not have the advance medicine we have today if it weren’t for the use of animals in research. For example, all the drugs we used nowadays have been tested previously on animals. We also owe a great deal of our anatomical and physiological knowledge to experiments involving test animals. Such experiments would be completely unethical to carry out on live humans and human trials could not be supported without the prior data from animal testing. A major problem with the issue of animals in research is that many people are misinformed or partially educated on the extensive criteria that are in place to ensure any displeasure of the animals is minimised. Laboratory animal science is a branch of science dedicated to improving the quality of animal experiments and their welfare. It involves anatomical knowledge of laboratory animals, their environmental needs, prevention and treatment of disease, experimental techniques, anaesthesia and euthanasia, alternative animal testing methods, and ethics. It is from this discipline of science, along with government bodies, that develop the guidelines for animal experimentation. These guidelines on animal testing can be summarised by the three R’s, a concept first discussed in the book, The Principles of Humane Experimental Technique (1). The 3 R’s stand for Replacement, Reduction, and Refinement. When any scientist is wishing to use animals for experimentation they must consider the three R’s and ask the following questions. Can the animals be replaced with any model organisms, cell cultures or simulations? What is the smallest amount of animals that can be used? How can the procedure be refined to reduce the amount of discomfort that the animal will experience?
All those questions are critical for the animals wellbeing, however the researcher also benefits from the 3 R’s. Some animal tests take months or years to conduct, and can cost anything from hundreds to millions of dollars for each substance being examined. In comparison to animal replacements, such as computer modelling techniques and cell-based in vitro methods, animal testing is more expensive (2) . So why aren’t these replacements always used?
When testing a new substance, using in silico or in vitro methods can be good indicators to how that substance may react. However, neither of them show how it reacts within a whole organism. Drug consumption, metabolism and excretion involves the entire organism, so it is necessary that it be examined in whole before human trials can begin.
Scientists are required to justify the number of animals used in their studies. Obviously researchers have morals and would prefer to not subject more animals to experimentation than necessary. Although, they have to consider their statistical analysis. Underpowered studies that do not include enough animal subjects may produce false data and mislead the investigator, which may result in an unreproducible experiment. In turn, underpowered studies unnecessarily subject animals to experimentation. To avoid this, scientists use two main methods to calculate the optimum number of animals needed; power analysis and the resource equation method, the first being the preferred method (3). These calculations ensure that no animal is being experimented on unnecessarily and in turn, being in accordance with the 3 R’s.
Refinement of an experiment is arguably the most important aspect when discussing an animals welfare. Ensuring an animal is under as little stress as possible is crucial in any research for two main reasons; animal ethics and undisrupted experiment results. If an animal is stressed in the laboratory environment, it can skew the results of a study, particularly in behavioural experiments (4). So it is in the best interest of a researcher to reduce any distress of the animal. This ensures a truer reading in results and is beneficial for the animal.
To summarise, animal testing may seem unethical but with today’s techniques and guidelines based around the 3 R’s, it is regulated to a humane level. In the future, animals may not be needed in research but for now, they play a critical role in advancing research and medicine.