Are There Alternatives to the Use of Animals in Research?
Some people contend that many animal experiments could be replaced by experiments that yield the same information without the use of animals. In fact, the present ability to replace animal experiments with alternatives such as tissue cultures, microorganisms, or computer models is very limited.22 Researchers have developed replacements for some animal experiments, and the search for alternatives is continuing. But if scientists could replace a large number of animal experiments with experiments that do not use animals, they would, because animals are expensive and difficult to use, and because scientists do not want to experiment on animals unnecessarily. Researchers who use animals do so because that is the best way to get the appropriate information.
Progress is being made in reducing the number of animals used in testing. Testing involves the use of animals, primarily rats and mice, to assess the safety or effectiveness of consumer products such as drugs, chemicals, and cosmetics. Many researchers are now searching for ways to further reduce the use of animals in testing, and these efforts could reduce the need for animals in research as well.
The term “alternatives” encompasses a range of options. In the research community, an alternative has been defined to mean reducing the number of animals used, refining experimental designs to lessen any pain or distress in animals, or replacing animals with other organisms or techniques.23 An alternative may therefore still involve the use of animals, but it might mean using fewer animals or using them in different ways.
Most researchers generally hold that nonanimal experiments are adjuncts rather than alternatives to animal experiments. Studies that do not use animals can produce much valuable information, but they cannot completely replace the information gained from animal experiments. Only animals can demonstrate the effects of a disease, injury, treatment, or preventive measure on a complex organism. For example, some aspects of the causation, treatment, or prevention of blindness cannot be studied in bacteria because they do not have eyes; some aspects of high blood pressure cannot be studied in protozoa because they do not have hearts or blood vessels; some aspects of arthritis cannot be studied in tissue culture cells without bones or joints.
New experimental procedures can sometimes reduce the numbers of animals used, particularly in the testing of new compounds for toxicity. For instance, new chemical compounds are now routinely screened in cell cultures, and if they are found to be toxic they are not given to animals. But cell cultures cannot replace animals. If a compound proves innocuous in a cell culture, it must still be tested in an animal to gauge its effects in a complex organism. Similarly, computer models and other nonanimal alternatives can at most supplement, rather than replace, animal experimentation.