The history of animal testing goes back to the writings of the Ancient Greeks in the 4th and 3rd centuries BCE, with Aristotle (384–322 BCE) and Erasistratus (304–258 BCE) one of the first documented to perform experiments on nonhuman animals. Galen, a physician in 2nd-century Rome, dissected pigs and goats, and is known as the "Father of Vivisection." Avenzoar, an Arabic physician in 12th-century Moorish Spain who also practiced dissection, introduced animal testing as an experimental method of testing surgical procedures before applying them to human patients. Although the exact purpose of the procedure was unclear, the Neolithic surgeon performed trepanation on a cow in 3400-3000 BCE. This is the earliest known surgery to have been performed on an animal, and it is possible that the procedure was done on a dead cow in order for the surgeon to practice their skills.
History of animal testing
In 1242, Ibn al-Nafis provided accurate descriptions of the circulation of blood in mammals. A complete description of this circulation was later provided in the 17th century by William Harvey. In his unfinished 1627 utopian novel, New Atlantis, scientist and philosopher Francis Bacon proposed a research center containing "parks and enclosures of all sorts of beasts and birds which we use ... for dissections and trials; that thereby we may take light what may be wrought upon the body of man." In the 1660s, the physicist Robert Boyle conducted many experiments with a pump to investigate the effects of rarefied air. He listed two experiments on living nonhuman animals: "Experiment 40", which tested the ability of insects to fly under reduced air pressure, and the dramatic "Experiment 41," which demonstrated the reliance of living creatures on the air for their survival. Boyle conducted numerous trials during which he placed a large variety of different nonhuman animals, including birds, mice, eels, snails and flies, in the vessel of the pump and studied their reactions as the air was removed. Here, he describes an injured lark:
…the Bird for a while appear'd lively enough; but upon a greater Exsuction of the Air, she began manifestly to droop and appear sick, and very soon after was taken with as violent and irregular Convulsions, as are wont to be observ'd in Poultry, when their heads are wrung off: For the Bird threw her self over and over two or three times, and died with her Breast upward, her Head downwards, and her Neck awry. In the 18th century, Antoine Lavoisier decided to use a guinea pig in a calorimeter because he wanted to prove that respiration was a form of combustion. He had an impression that combustion and respiration are chemically identical. Lavoisier demonstrated this with the help of Pierre-Simon Laplace. They both carefully measured the amount of "carbon dioxide and heat given off by a guinea pig as (they) breathed". Then they contrasted this to "the amount of heat produced when they burned carbon to produce the same amount of carbon dioxide as had been exhaled by the guinea pig". Their conclusion made Lavoisier confident "that respiration is a form of combustion". Also, the result showed that the heat mammals produce through respiration allowed their bodies to be above room temperature. In the second volume of his Statical Essays, Haemastaticks (1733), Stephen Hales accounts several different experiments he conducted on animals. One of his most notable experiments is one he conducted on an unanesthetized elderly mare. He devised a contraption using a brass canula, the excised windpipe of a goose, and a tall glass tube to observe the horse's "force of blood." Because of this, Hales is recognized as being the first person to measure blood pressure. In the 1780s, Luigi Galvani demonstrated that electricity applied to a dead, dissected, frog's leg muscle caused it to twitch, which led to an appreciation for the relationship between electricity and animation. In the 1880s, Louis Pasteur convincingly demonstrated the germ theory of medicine by giving anthrax to sheep. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning. In 1921 Otto Loewi provided the first substantial evidence that neuronal communication with target cells occurred via chemical synapses. He extracted two hearts from frogs and left them beating in an ionic bath. He stimulated the attached Vagus nerve of the first heart and observed its beating slowed. When the second heart was placed in the ionic bath of the first, it also slowed. In the 1920s, Edgar Adrian formulated the theory of neural communication that the frequency of action potentials, and not the size of the action potentials, was the basis for communicating the magnitude of the signal. His work was performed in an isolated frog nerve-muscle preparation. Adrian was awarded a Nobel Prize for his work. In the 1960s David Hubel and Torsten Wiesel demonstrated the macro columnar organization of visual areas in cats and monkeys, and provided physiological evidence for the critical period for the development of disparity sensitivity in vision (i.e.: the main cue for depth perception), and were awarded a Nobel Prize for their work. In 1996 Dolly the sheep was born, the first mammal to be cloned from an adult cell. The process by which Dolly the sheep was cloned utilized a process known as nuclear transfer applied by lead scientist Ian Wilmut. Although other scientists were not immediately able to replicate the experiment, Wilmut argued that the experiment was indeed repeatable, given a timeframe of over a year. In 1997, innovations in frogs, Xenopus laevis, by developmental biologist Jonathan Slack of the University of Bath, created headless tadpoles, which could allow future applications in donor organ transplantation. There has been growing concern about both the methodology and the care of animals in laboratories who are used in testing. There is increasing emphasis on more humane and compassionate treatment of other animals. Methodological concerns include factors that make animal study results less reproducible than intended. For example, a 2014 study from McGill University in Montreal, Canada suggests that mice handled by men rather than women showed higher stress levels.
In medicine
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