In broad terms, animals are used in experiments as in vivo models – living, intact biological systems – and as sources of tissues, cells, and organs. Animal experimentation is usually defended as a way to solve specific problems, including the understanding and treatment of human disease. But animals are also used in what is categorized as basic research, which seeks to increase our knowledge of the way organisms behave, develop and function biologically.
It is estimated that at least 100 million animals are used every year in the multibillion dollar research industry that includes university, pharmaceutical and diagnostic laboratories, and military, agricultural and marine mammal facilities. But because the most commonly used animals – rats, mice, and birds – are not counted, the exact number is not known.
The scope of animal use in science today includes virtually every field of investigation, including:
- As models for human diseases in medical research and drug development.
- In psychological and behavioral research, such as addiction studies and maternal deprivation experiments.
- For “spare parts” such as heart valves, which may be harvested from a human donor or recovered from a cow or pig as a by-product of the slaughter industry.
- As living incubators to produce substances such as insulin (although biosynthetic insulin has largely replaced the use of animal insulin) and monoclonal antibodies employed in medicine and biomedical research.
- For military training, weapons development and to study the effects of space exploration.
- In veterinary medicine, to study the diseases or conditions common to a given species.
- To study basic anatomy and physiological principles.
- To test scientific theories and principles, or simply to gain knowledge often with no specific application in mind.
How Many Animals are Used in Research?
Who Counts? Who Doesn't?
Examples of Animals Used in Research
Examples of Areas of Research that Use Animals
Where the Animals are Used
The History of Vivisection