Animal testing

Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals in experiments to answer scientific and medical questions. This type of research is done in places like universities, medical schools, and pharmaceutical companies. It ranges from pure research, which aims to understand how living things work, to applied research, which looks for practical solutions like cures for diseases.

Research using animals has been very important for modern medicine. It has helped us learn about human physiology and biochemistry and has led to major advances such as the near-eradication of polio and the development of organ transplantation. Important discoveries like the role of chromosomes in inheritance and the development of insulin for diabetes came from studying animals. Many treatments and medical tools we use today, like antibiotics and general anaesthetics, were also developed through animal research.

Animal testing is often used when testing on humans is not possible or would be unethical. Scientists choose animal models that react in ways similar to humans, which helps them understand diseases without risking harm to people. While results from animals don’t always apply directly to humans, many important medical breakthroughs have relied on this kind of research.

Millions of animals are used each year in research around the world. In 2015, it was estimated that about 192 million vertebrate animals were used. Mice and rats are the most common animals used. Regulations about animal testing differ between countries, and there is ongoing discussion about the ethics and necessity of animal testing. Researchers are also exploring alternatives, such as computer models and new technologies that could reduce or replace the need for animal testing.

Definitions

The terms animal testing, animal experimentation, animal research, in vivo testing, and vivisection all refer to using animals to answer scientific and medical questions, but they have different meanings to different people. "Vivisection" literally means cutting into a living animal and used to describe experiments where animals are cut open while alive. Some people who oppose animal testing use this word to describe any kind of experiment on living animals, but scientists usually prefer the term "animal experimentation".

This section focuses on research using animals and does not include discussions about veterinary surgery on animals.

History

Main article: History of animal testing

The earliest references to animal testing are found in the writings of the Greeks in the 2nd and 4th centuries BCE. Aristotle and Erasistratus were among the first to perform experiments on living animals. Discoveries in the 18th and 19th centuries included Antoine Lavoisier’s use of a guinea pig to prove that respiration was a form of combustion, and Louis Pasteur’s demonstration of the germ theory of disease using anthrax in sheep.

Research using animal models has been central to most of the achievements of modern medicine. It has contributed to fields such as human physiology and biochemistry, and has played significant roles in areas like neuroscience and infectious disease. For example, the results have included the near-eradication of polio and the development of organ transplantation, benefiting both humans and animals.

Model organisms

Main article: Model organism

Scientists use animals called model organisms to study how living things work. These animals help us learn about health and disease. Some of the most common model organisms are invertebrates like fruit flies and nematode worms. These small creatures are easy to care for and have short life cycles, making them useful for many experiments. However, because their bodies work differently from humans, they can only tell us so much about human health.

Other common model organisms include rodents like mice and rats. Mice are especially popular because they share many genes with humans and can be used to study inherited diseases. Dogs are also used in research, particularly beagles, for studying heart and bone diseases. Zebrafish are small fish that are used to study cancers and other diseases because they are easy to care for and share some similarities with human cells. Non-human primates, such as monkeys, are used for studying diseases like AIDS and for neurological research, though their use is carefully regulated.

Care and use of animals

Regulations and laws

See also: Animal testing regulations, Institutional Animal Care and Use Committee, Animals (Scientific Procedures) Act 1986, and European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes

Rules about using animals in labs differ depending on where you are and what kind of animal is involved. In the U.S., special committees called Institutional Animal Care and Use Committees (IACUCs) help make sure experiments are done properly and that steps are taken to reduce any pain for the animals. These committees also check to see if there are other ways to do the research without using animals. The U.S. government watches over these rules to help protect the animals.

Numbers

It’s hard to know exactly how many animals are used in testing around the world, but some estimates say about 100 million vertebrates are used each year. In the U.S. alone, more than 800,000 animals were used in 2016. This includes animals like dogs, cats, and monkeys, but not mice and rats, which are very commonly used too. The numbers have changed over time, with fewer dogs and cats being used now than in the past.

The Three Rs

Main article: Three Rs (animal research)

Scientists try to make animal testing more ethical by following three important ideas called the Three Rs. Replacement means finding ways to do research without using animals at all, like using computers. Reduction means using as few animals as possible and getting the most information from them. Refinement means making sure any animals that are used feel as little stress or pain as possible. These ideas help make animal testing better for both the animals and the science.