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About Animal Testing

Humane Society International / Global

What is animal testing?

The term “animal testing” refers to procedures performed on living animals for purposes of research into basic biology and diseases, assessing the effectiveness of new medicinal products, and testing the human health and/or environmental safety of consumer and industry products such as cosmetics, household cleaners, food additives, pharmaceuticals and industrial/agro-chemicals. All procedures, even those classified as “mild,” have the potential to cause the animals physical as well as psychological distress and suffering. Often the procedures can cause a great deal of suffering. Most animals are killed at the end of an experiment, but some may be re-used in subsequent experiments. Here is a selection of common animal procedures:

• Forced chemical exposure in toxicity testing, which can include oral force-feeding, forced inhalation, skin or injection into the abdomen, muscle, etc.
• Exposure to drugs, chemicals or infectious disease at levels that cause illness, pain and distress, or death
• Genetic manipulation, e.g., addition or “knocking out” of one or more genes
• Ear-notching and tail-clipping for identification
• Short periods of physical restraint for observation or examination
• Prolonged periods of physical restraint
• Food and water deprivation
• Surgical procedures followed by recovery
• Infliction of wounds, burns and other injuries to study healing
• Infliction of pain to study its physiology and treatment
• Behavioural experiments designed to cause distress, e.g., electric shock or forced swimming
• Other manipulations to create “animal models” of human diseases ranging from cancer to stroke to depression
• Killing by carbon dioxide asphyxiation, neck-breaking, decapitation, or other means

What types of animals are used?

Many different species are used around the world, but the most common include mice, fish, rats, rabbits, guinea pigs, hamsters, farm animals, birds, cats, dogs, mini-pigs, and non-human primates (monkeys, and in some countries, chimpanzees). Video: Watch what scientists have to say about alternatives to animal testing .

It is estimated that more than 115 million animals worldwide are used in laboratory experiments every year. But because only a small proportion of countries collect and publish data concerning animal use for testing and research, the precise number is unknown. For example, in the United States, up to 90 percent of the animals used in laboratories (purpose-bred rats, mice and birds, fish, amphibians, reptiles and invertebrates) are excluded from the official statistics, meaning that figures published by the U.S. Department of Agriculture are no doubt a substantial underestimate.

Within the European Union, more than 12 million animals are used each year, with France, Germany and the United Kingdom being the top three animal using countries. British statistics reflect the use of more than 3 million animals each year, but this number does not include animals bred for research but killed as “surplus” without being used for specific experimental procedures. Although these animals still endure the stresses and deprivation of life in the sterile laboratory environment, their lives are not recorded in official statistics. HSI believes that complete transparency about animal use is vital and that all animals bred, used or killed for the research industry should be included in official figures. See some animal use statistics .

What’s wrong with animal testing?

For nearly a century, drug and chemical safety assessments have been based on laboratory testing involving rodents, rabbits, dogs, and other animals. Aside from the ethical issues they pose—inflicting both physical pain as well as psychological distress and suffering on large numbers of sentient creatures—animal tests are time- and resource-intensive, restrictive in the number of substances that can be tested, provide little understanding of how chemicals behave in the body, and in many cases do not correctly predict real-world human reactions. Similarly, health scientists are increasingly questioning the relevance of research aimed at “modelling” human diseases in the laboratory by artificially creating symptoms in other animal species.

Trying to mirror human diseases or toxicity by artificially creating symptoms in mice, dogs or monkeys has major scientific limitations that cannot be overcome. Very often the symptoms and responses to potential treatments seen in other species are dissimilar to those of human patients. As a consequence, nine out of every 10 candidate medicines that appear safe and effective in animal studies fail when given to humans. Drug failures and research that never delivers because of irrelevant animal models not only delay medical progress, but also waste resources and risk the health and safety of volunteers in clinical trials.

What’s the alternative?

If lack of human relevance is the fatal flaw of “animal models,” then a switch to human-relevant research tools is the logical solution. The National Research Council in the United States has expressed its vision of “a not-so-distant future in which virtually all routine toxicity testing would be conducted in human cells or cell lines”, and science leaders around the world have echoed this view.

The sequencing of the human genome and birth of functional genomics, the explosive growth of computer power and computational biology, and high-speed robot automation of cell-based (in vitro) screening systems, to name a few, has sparked a quiet revolution in biology. Together, these innovations have produced new tools and ways of thinking that can help uncover exactly how chemicals and drugs disrupt normal processes in the human body at the level of cells and molecules. From there, scientists can use computers to interpret and integrate this information with data from human and population-level studies. The resulting predictions regarding human safety and risk are potentially more relevant to people in the real world than animal tests.

But that’s just the beginning. The wider field of human health research could benefit from a similar shift in paradigm. Many disease areas have seen little or no progress despite decades of animal research. Some 300 million people currently suffer from asthma, yet only two types of treatment have become available in the last 50 years. More than a thousand potential drugs for stroke have been tested in animals, but only one of these has proved effective in patients. And it’s the same story with many other major human illnesses. A large-scale re-investment in human-based (not mouse or dog or monkey) research aimed at understanding how disruptions of normal human biological functions at the levels of genes, proteins and cell and tissue interactions lead to illness in our species could advance the effective treatment or prevention of many key health-related societal challenges of our time.

Modern non-animal techniques are already reducing and superseding experiments on animals, and in European Union, the “3Rs” principle of replacement, reduction and refinement of animal experiments is a legal requirement. In most other parts of the world there is currently no such legal imperative, leaving scientists free to use animals even where non-animal approaches are available.

If animal testing is so unreliable, why does it continue?

Despite this growing evidence that it is time for a change, effecting that change within a scientific community that has relied for decades on animal models as the “default method” for testing and research takes time and perseverance. Old habits die hard, and globally there is still a lack of knowledge of and expertise in cutting-edge non-animal techniques.

But with HSI’s help, change is happening. We are leading efforts globally to encourage scientists, companies and policy-makers to transition away from animal use in favour of 21st century methods. Our work brings together experts from around the globe to share knowledge and best practice, improving the quality of research by replacing animals in the laboratory.

Are animal experiments needed for medical progress?

It is often argued that because animal experiments have been used for centuries, and medical progress has been made in that time, animal experiments must be necessary. But this is missing the point. History is full of examples of flawed or basic practices and ideas that were once considered state-of-the-art, only to be superseded years later by something far more sophisticated and successful. In the early 1900’s, the Wright brothers’ invention of the airplane was truly innovative for its time, but more than a century later, technology has advanced so much that when compared to the modern jumbo jet those early flying machines seem quaint and even absurd. Those early ideas are part of aviation history, but no-one would seriously argue that they represent the cutting-edge of design or human achievement. So it is with laboratory research. Animal experiments are part of medical history, but history is where they belong. Compared to today’s potential to understand the basis of human disease at cellular and molecular levels, experimenting on live animals seems positively primitive. So if we want better quality medical research, safer more effective pharmaceuticals and cures to human diseases, we need to turn the page in the history books and embrace the new chapter—21st century science.

Independent scientific reviews demonstrate that research using animals correlates very poorly to real human patients. In fact, the data show that animal studies fail to predict real human outcomes in 50 to 99.7 percent of cases. This is mainly because other species seldom naturally suffer from the same diseases as found in humans. Animal experiments rely on often uniquely human conditions being artificially induced in non-human species. While on a superficial level they may share similar symptoms, fundamental differences in genetics, physiology and biochemistry can result in wildly different reactions to both the illness and potential treatments. For some areas of disease research, overreliance on animal models may well have delayed medical progress rather than advanced it. By contrast, many non-animal replacement methods such as cell-based studies, silicon chip biosensors, and computational systems biology models, can provide faster and more human-relevant answers to medical and chemical safety questions that animal experiments cannot match.

“The claim that animal experimentation is essential to medical development is not supported by proper, scientific evidence but by opinion and anecdote. Systematic reviews of its effectiveness don’t support the claims made on its behalf” (Pandora Pound et al. British Medical Journal 328, 514-7, 2004).

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Imagine a syringe being forced down your throat to inject a chemical into your stomach, or being restrained and forced to breathe sickening vapours for hours. That’s the cruel reality of animal testing for millions of mice, rabbits, dogs and other animals worldwide.

We’re giving the beauty industry a cruelty-free makeover with a wave of animal testing bans supported by hundreds of companies and millions of caring consumers worldwide.

We all dream of the day when cancer is cured and AIDS is eradicated, but is the continued use of mice, monkeys and other animals as experimental “models” of human disease actually holding us back from realizing the promise of 21st century science?

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• About Animal Testing /
• current page What is animal testing?

What is animal testing?

An introduction to animal experiments

What are animal experiments?

An animal test is any scientific experiment or test in which a live animal is forced to undergo something that is likely to cause them pain, suffering, distress or lasting harm. 

Animal experiments are not the same as taking your companion animal to the vet. Animals used in laboratories are deliberately harmed, not for their own good, and are usually killed at the end of the experiment.

Animal experiments include:

• injecting or force feeding animals with potentially harmful substances
• surgically removing animals’ organs or tissues to deliberately cause damage
• forcing animals to inhale toxic gases
• subjecting animals to frightening situations to create anxiety and depression.

Some experiments require the animal to die as part of the test. For example, regulatory tests for botox, vaccines and some tests for chemical safety are essentially variations of the cruel Lethal Dose 50 test in which 50% of the animals die or are killed just before the point of death.

Which animals are used?

A surprisingly, large range of animal species are regularly used in experiments, including wild animals.

Only vertebrate animals (mammals, birds, fish and amphibians) and some invertebrates such as octopuses are defined as “animals” by European legislation governing animal experiments.  Shockingly, in the USA rats, mice, fish, amphibians and birds are not defined as animals under animal experiment regulations. That means no legal permission to experiment on them is needed and they are not included in any statistics.

Animals used in experiments are usually bred for this purpose by the laboratory or in breeding facilities. It’s a cruel, multi-million dollar industry. We believe that all animals are equally important. A dog bred for research is still a dog who could otherwise live a happy life in a loving home.

Some monkeys are still trapped in the wild in Africa, Asia and South America to be used in experiments or imprisoned in breeding facilities. Their children are exported to laboratories around the world. The use of wild-caught monkeys in experiments is generally banned in Europe but is allowed elsewhere.

Horses and other animals such as cows, sheep and pigs are often supplied by dealers and may originate from racing stables or farms for use in animal experiments. The rules preventing the use of stray companion animals like dogs and cats vary from country to country.

Wild animals can be used in trapping and monitoring experiments in the wild, or they may be captured and brought into a laboratory setting for more invasive research, sometimes in the name of conservation.

What are laboratories like?

Laboratories are no place for any animal. They are typically sterile, indoor environments in which the animals are forced to live in cages, pens or Perspex boxes – denied complete freedom of movement and control over their lives. Some animals in laboratories are confined on their own, without the companionship of others.

Our investigations show time and time again that, despite claims by the animal research community, life inside a laboratory is no life at all.

The science relating to animal experiments can be extremely complicated and views often differ. What appears on this website represents Cruelty Free International expert opinion, based on a thorough assessment of the evidence.

Investigations

Breaking investigation once again reveals shocking cruelty and abuse faced by animals in European laboratory

Toxicity testing on animals at Vivotecnia, Spain

subtitle: Breaking investigation once again reveals shocking cruelty and abuse faced by animals in European laboratory

Investigation

Undercover video footage reveals terrible plight of animals at Laboratory of Pharmacology and Toxicology

Toxicity testing at LPT, Germany

subtitle: Undercover video footage reveals terrible plight of animals at Laboratory of Pharmacology and Toxicology

Exposed: Appalling suffering at a UK animal testing laboratory

Veterinary schools using dogs, Japan

subtitle: Exposed: Appalling suffering at a UK animal testing laboratory

Street dogs are being used in student veterinary classes

Investigation at Khon Kaen University, Thailand

subtitle: Street dogs are being used in student veterinary classes

Our investigation uncovers the horror of life for monkeys in a top European animal experiments laboratory

Monkey experiments at Max Planck Institute, Germany

subtitle: Our investigation uncovers the horror of life for monkeys in a top European animal experiments laboratory

Investigation at University of Cambridge, United Kingdom

A Cruelty Free International investigation in 2013 uncovered the shocking use of very young puppies and kittens in animal experiments in a UK laboratory.

Dog and cat experiments at MSD Animal Health, United Kingdom

subtitle: A Cruelty Free International investigation in 2013 uncovered the shocking use of very young puppies and kittens in animal experiments in a UK laboratory.

Our investigation exposes the cruel use of wild baboons in for animal experiments

Experiments on wild baboons in Kenya

subtitle: Our investigation exposes the cruel use of wild baboons in for animal experiments

We uncovered the terrible plight of animals used in research at this ‘world-leading’ UK university.

Animal experiments at Imperial College London, United Kingdom

subtitle: We uncovered the terrible plight of animals used in research at this ‘world-leading’ UK university.

Animal experiments at Wickham Laboratories, United Kingdom

• History of Animal Testing

Animals are used to develop medical treatments, determine the toxicity of medications, check the safety of products destined for human use, and other biomedical , commercial, and health care uses. Research on living animals has been practiced since at least 500 BC. [ 2 ]

Early History

Descriptions of the dissection of live animals have been found in ancient Greek writings from as early as circa 500 BC. Physician-scientists such as Aristotle , Herophilus , and Erasistratus performed the experiments to discover the functions of living organisms. Vivisection (dissection of a living organism) was practiced on human criminals in ancient Rome and Alexandria, but prohibitions against mutilation of the human body in ancient Greece led to a reliance on animal subjects. Aristotle believed that animals lacked intelligence, and so the notions of justice and injustice did not apply to them. Theophrastus , a successor to Aristotle, disagreed, objecting to the vivisection of animals on the grounds that, like humans, they can feel pain, and causing pain to animals was an affront to the gods. [ 79 ] [ 80 ]

Roman physician and philosopher Galen (130-200 AD), whose theories of medicine were influential throughout Europe for fifteen centuries, engaged in the public dissection of animals (including an elephant), which was a popular form of entertainment at the time. Galen also engaged in animal vivisection in order to develop theories on human anatomy, physiology, pathology, and pharmacology. In one of his experiments, he demonstrated that arteries, which were believed by earlier physicians to contain air, actually contained blood. Galen believed that animal physiology was very similar to that of human beings, but despite this similarity he had little sympathy for the animals on which he experimented. Galen recommended that his students vivisect animals “without pity or compassion” and warned that the “unpleasing expression of the ape when it is being vivisected” was to be expected. [ 80 ] [ 82 ] [ 81 ]

French philosopher René Descartes (1596-1650), who occasionally experimented on live animals, including at least one rabbit, as well as eels and fish, believed that animals were “automata” who could not experience pain or suffer the way that humans do. Descartes recognized that animals could feel, but because they could not think, he argued, they were unable to consciously experience those feelings. [ 66 ] [ 83 ]

English Physician William Harvey (1578-1657) discovered that the heart, and not the lungs, circulated blood throughout the body as a result of his experiments on living animals. [ 84 ] [ 85 ]

Animal Testing in the 1800s and Early 1900s

There was little public objection to animal experimentation until the 19th Century, when the increased adoption of domestic pets fueled interest in an anti-vivisection movement, primarily in England. This trend culminated in the founding of the Society for the Protection of Animals Liable to Vivisection in 1875, followed by the formation of similar groups. [ 79 ] [ 87 ]

One of the first proponents of animal testing to respond to the growing anti-testing movement was French physiologist Claude Bernard in his Introduction to the Study of Experimental Medicine (1865). Bernard argued that experimenting on animals was ethical because of the benefits to medicine and the extension of human life. [ 79 ]

Queen Victoria was an early opponent of animal testing in England, according to a letter written by her private secretary in 1875: “The Queen has been dreadfully shocked at the details of some of these [animal research] practices, and is most anxious to put a stop to them.” Soon the anti-vivisection campaign became strong enough to pressure lawmakers into establishing the first laws controlling the use of animals for research: Great Britain’s Cruelty to Animals Act of 1876 . [ 15 ] [ 88 ]

Russian physiologist Ivan Pavlov (1849-1936) demonstrated the “conditioned reflex” by training dogs to salivate upon hearing the sound of a bell or electric buzzer. In order to measure “the intensity of the salivary reflex,” wrote Pavlov, the dogs were subjected to a “minor operation, which consists in the transplantation of the opening of the salivary duct from its natural place on the mucous membrane of the mouth to the outside skin.” A “small glass funnel” was then attached to the salivary duct opening with a “special cement.” [ 86 ] [ 75 ]

In 1959, The Principles of Humane Experimental Technique by zoologist William Russell and microbiologist Rex Burch was published in England. The book laid out the principle of the “Three Rs” for using animals in research humanely: Replacement (replacing the use of animals with alternative research methods), Reduction (minimizing the use of animals whenever possible), and Refinement (reducing suffering and improving animals’ living conditions). The “Three Rs” were incorporated into the AWA and have formed the basis of many international animal welfare laws. [ 89 ] [ 90 ] [ 91 ]

Animals in Space and the Military

Since as early as 1948, animals have been used by the US space program for testing such aspects of space travel as the effects of prolonged weightlessness. After several monkeys died in unmanned space flights carried out during the 1940s, the first monkey to survive a space flight was Yorick, recovered from an Aerobee missile flight on Sep. 20, 1951. However, Yorick died several hours after landing, possibly due to heat stress. The first living creature to orbit the Earth was Laika , a stray dog sent into space on the Soviet spacecraft Sputnik 2 in Nov. 1957. Laika died of “overheating and panic” early in the mission, according to the BBC. The record for the most animals sent into space was set Apr. 17, 1998, when more than two thousand animals, including rats, mice, fish, crickets, and snails, were launched into space on the shuttle Columbia (along with the seven-member human crew) for neurological testing. [ 7 [ 8 ] [ 92 ] [ 116 ]

Since the Vietnam war , animals have also been used by the US military. The US Department of Defense used 488,237 animals for research and combat trauma training (“live tissue training”) in fiscal year 2007 (the latest year for which data are available), which included subjecting anesthetized goats and pigs to gunshot wounds, burns, and amputations for the training of military medics. In February 2013, after an escalation of opposition by animal rights groups such as People for the Ethical Treatments of Animals (PETA), Congress ordered the Pentagon to present a written plan to phase out live tissue training. The US Coast Guard, however, which was at the center of a 2012 scandal involving videotaped footage of goats being mutilated as part of its live tissue training program, said in May 2013 that the program will continue. [ 6 ] [ 93 ] [ 94 ] [ 95 ]

Regulations

A public outcry over animal testing and the treatment of animals in general broke out in the United States in the mid-1960s, leading to the passage of the AWA. An article in the November 29, 1965 issue of Sports Illustrated about Pepper, a farmer’s pet Dalmatian that was kidnapped and sold into experimentation, is believed to have been the initial catalyst for the rise in anti-testing sentiment. Pepper died after researchers attempted to implant an experimental cardiac pacemaker in her body. [ 74 ] [ 75 ]

Animal testing in the United States is regulated by the federal Animal Welfare Act (AWA), passed in 1966 and amended in 1970, 1976, and 1985. The AWA defines “animal” as “any live or dead dog, cat, monkey (nonhuman primate mammal), guinea pig, hamster, rabbit, or such other warm blooded animal.” The AWA excludes birds, rats and mice bred for research, cold-blooded animals, and farm animals used for food and other purposes. [ 3 ] [ 27 ]

The AWA requires that each research facility develop an internal Institutional Animal Committee (more commonly known as an Institutional Animal Care and Use Committee, or IACUC) to “represent society’s concerns regarding the welfare of animal subjects.” The Committee must be comprised of at least three members. One member must be a veterinarian and one must be unaffiliated with the institution. [ 3 ] [ 27 ]

While the AWA regulates the housing and transportation of animals used for research, it does not regulate the experiments themselves. The U.S. Congress Conference Committee stated at the time of the bill’s passage that it wanted “to provide protection for the researcher… by exempting from regulations all animals during actual research and experimentation… It is not the intention of the committee to interfere in any way with research or experimentation.” [ 66 ]

Animal studies funded by US Public Health Service (PHS) agencies, including the National Institutes of Health (NIH), are further regulated by the Public Health Service Policy on Humane Care and Use of Laboratory Animals. [ 27 ] All PHS funded institutions must base their animal care standards on the AWA and the Guide for the Care and Use of Laboratory Animals (also known as “the Guide “), prepared by the Institute for Laboratory Animal Research at the National Research Council. Unlike the AWA, the Policy on Humane Care and Use of Laboratory Animals and the Guide cover all vertebrate animals used for research, including birds, rats and mice. The Guide “establishes the minimum ethical, practice, and care standards for researchers and their institutions,” including environment and housing standards and required veterinary care. The Guide stipulates that “the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative.” [ 71 ]

The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) reports the number of animals used for research each year, though it excludes animals not covered by the AWA. For fiscal year 2010 (the latest year for which data are available as of Oct. 11, 2013), 1,134,693 animals were reported. Since the data excludes cold-blooded animals, farm animals used for food, and birds, rats, and mice bred for use in research, the total number of animals used for testing is unknown. Estimates of the number of animals not counted by APHIS range from 85%-96% of the total of all animals used for testing. [ 1 ] [ 2 ] [ 26 ] [ 65 ] [ 72 ]

The USDA breaks down its data by three categories of pain type: animals that experience pain during their use in research but are given drugs to alleviate it; animals who experience pain and are not given drugs; and animals who do not experience pain and are not given drugs. [ 26 ]

The U.S. Food and Drug Administration (FDA), which regulates the development of new medications, states that “At the preclinical stage, the FDA will generally ask, at a minimum, that sponsors… determine the acute toxicity of the drug in at least two species of animals.” [ 73 ]

On Dec. 29, 2022, President Joe Biden signed the FDA Modernization Act 2.0. Sponsored by Senator Rand Paul (R-KY), the law updates the U.S. Federal Food, Drug, and Cosmetic Act by eliminating the requirement that pharmaceutical companies test new drugs on animals before human trials. The amendment does not prevent companies from performing animals tests, but makes the tests the choice of the company. [ 151 ]

The Modern Debate

The 1975 publication of Animal Liberation by Australian philosopher Peter Singer galvanized the animal rights and anti-testing movements by popularizing the notion of “speciesism” as being analogous to racism, sexism, and other forms of prejudice. Addressing animal testing specifically, Singer predicted that “one day… our children’s children, reading about what was done in laboratories in the twentieth century, will feel the same sense of horror and incredulity… that we now feel when we read about the atrocities of the Roman gladiatorial arenas or the eighteenth-century slave trade.” [ 66 ]

In 1981, an early victory by then-fledgling animal rights group People for the Ethical Treatment of Animals (PETA) served to revitalize the anti-testing movement once again. A PETA activist working undercover at the Institute for Biological Research in Silver Spring, MD took photographs of monkeys in the facility that had engaged in self-mutilation due to stress. The laboratory’s director, Edward Taub, was charged with more than a dozen animal cruelty offenses, and an especially notorious photo of a monkey in a harness with all four limbs restrained became a symbolic image for the animal rights movement. [ 96 ]

In 2001, controversy erupted over animal experiments undertaken by a veterinarian at Ohio State University. Dr. Michael Podell infected cats with the feline AIDS virus in order to study why methamphetamine users deteriorate more quickly from the symptoms of AIDS. After receiving several death threats, Dr. Podell abandoned his academic career. Over 60% of biomedical scientists polled by Nature magazine say “animal-rights activists present a real threat to essential biomedical research.” [ 35 ] [ 97 ]

A 2007 report by the National Research Council of the National Academy of Sciences called for a reduction in the use of animal testing, recommending instead the increased use of in vitro methods using human cells. Though the report touted new technologies that could eventually eliminate the need for animal testing altogether, the authors acknowledged that “For the foreseeable future… targeted tests in animals would need to be used to complement the in vitro tests, because current methods cannot yet adequately mirror the metabolism of a whole animal.” [ 104 ]

In Mar. 2013, the European Union banned the import and sale of cosmetic products that use ingredients tested on animals. Some proponents of animal testing objected, arguing that some animal tests had no non-animal equivalents. A spokesman for the trade association Cosmetics Europe stated it is likely “that consumers in Europe won’t have access to new products because we can’t ensure that some ingredients will be safe without access to suitable and adequate testing.” India and Israel have also banned animal testing for cosmetic products, while the United States has no such ban in place. [ 98 ] [ 99 ]

China is the only major market where testing all cosmetics on animals is required by law, and foreign companies distributing their products to China must also have them tested on animals. China announced that its animal testing requirement will be waived for shampoo, perfume, and other so-called “non-special use cosmetics” manufactured by Chinese companies after June 2014. “Special use cosmetics,” including hair regrowth, hair removal, dye and permanent wave products, antiperspirant, and sunscreen, will continue to warrant mandatory animal testing. China’s National Medical Products Administration announced that animal testing for “ordinary” cosmetics (those that do not make claims such as “anti-aging”) will no longer be required as of May 2021. [ 43 ] [ 65 ] [ 114 ] [ 149 ]

After ceasing to breed chimpanzees for research in May 2007, the US National Institutes of Health announced in June 2013 that it would retire most of its chimpanzees (310 in total) over the next several years. While the decision was welcomed by animal rights groups, opponents said the decision would have a negative impact on the development of critical vaccines and treatments. The Texas Biomedical Research Institute released a statement claiming that the number of chimps to be retained (up to 50) was “not sufficient to enable the rapid development of better preventions and cures for hepatitis B and C, which kill a million people every year.” On Nov. 18, 2015 the US National Institutes of Health announced that its remaining 50 research chimpanzees will be retired to the Federal Chimpanzee Sanctuary System. Gabon remains the only country in the world that still experiments on chimpanzees. [ 4 ] [ 100 ] [ 117 ]

The Environmental Protection Agency (EPA) released a plan on Sep. 10, 2019 to reduce studies using mammal testing by 30% by 2025 and to eliminate the mammal testing altogether by 2035. In Nov. 2019, the FDA enacted a policy allowing some lab animals used for animal testing to be sent to shelters and sanctuaries for adoption. The National Institutes of Health (NIH) adopted a similar policy in Aug. 2019 and the Department of Veterans Affairs (VA) did so in 2018. [ 131 ] [ 146 ]

On Sep. 2, 2021, Mexico became the 41st country and first in North America to ban cosmetics testing on animals, according to the Humane Society International. [ 150 ]

Animal Testing and COVID-19

The COVID-19 (coronavirus) global pandemic brought attention to the debate about animal testing as researchers sought to develop a vaccine for the virus as quickly as possible. Vaccines are traditionally tested on animals to ensure their safety and effectiveness. News broke in Mar. 2020 that there was a shortage of the genetically modified mice that were needed to test coronavirus vaccines. [ 133 ]

Meanwhile, other companies tried new development techniques that allowed them to skip animal testing and start with human trials. Moderna Therapeutics used a synthetic copy of the virus genetic code instead of a weakened form of the virus. The FDA approved an application for Moderna to begin clinical trials on a coronavirus vaccine on Mar. 4, 2020, and the first participant was dosed on Mar. 16, 2020. [ 143 ] [ 147 ]

A shortage of monkeys, including pink-faced rhesus macaques, threatened vaccine development at the beginning of the pandemic and as variants of COVID-19 were found. The monkeys were previously flown in from China, but a ban on wildlife imports from China forced researchers to look elsewhere, a difficult task as China previously supplied over 60% of research monkeys in the United States. [ 148 ]

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Why Do Scientists Experiment on Animals?

Animal studies in science are experiments that control an animal's behaviour or physiology for study, often to serve as a model for human biology where testing on humans is impractical or unethical.

The species or classification of animals used in testing largely depends on the goal of the experiment.

For example, zebrafish are quick to breed, easy to house, and transparent as embryos - but they also carry 70 percent of the genes found in humans. All this makes them suitable for studies on human disease and embryological development.

Rodents have a long history of being used for science experiments, and today make up around three quarters of all animal subjects in testing. Easy to raise and breed, their mammalian physiology and genomes overlap even more considerably with those of humans, making them suitable models for studying behaviours, toxicology, and the effects of medical treatments.

Non-human primates , especially chimpanzees and rhesus monkeys, have also been used extensively in scientific testing. While harder to reproduce in large numbers and challenging to house comfortably, experiments on our closest evolutionary relatives can yield valuable information on a wide range of issues, from drug toxicity to neurology.

However, the close likeness of non-human primates to ourselves also means their use in experiments is the most controversial of all types of animal testing . Generally, data across different countries, including the European Union , show that non-human primate research constitutes less than 1 percent of all animal studies.

However, studies on monkeys aren't yet phased out: In 2017, the US had a record-high number of studies involving monkeys.

How useful are animal models in experiments?

If conducted under strict methods with appropriate protocols, animal experimentation can provide reliable evidence on how that animal's physiology or behaviour responds under the experiment's conditions; genetic studies are particularly effective, while behavioural studies can yield less firm conclusions.

Unfortunately, the nature of experiments that make use of animal models can often lend themselves to being poorly designed, conducted, or analysed. There can also be a sex imbalance, with much of rodent research done only on male mice , for example.

Experiments that apply the findings to human biology require significant assumptions on whether any differences between them are significant. Even where animals are genetically altered to better reflect human biochemistry, there is always the risk that an unidentified behaviour or function might mean the experimental results can't be applied to humans.

This doesn't make animal models useless. As with all experiments, the weight of replicated experiments performed critically under peer review determines how confident we should be in a set of results.

It does mean we ought to be cautious about how results from an experiment based on an animal model might apply to our own bodies.

What are the ethics of testing on animals?

Concerns surrounding experiments using animal models are often based on the morality of depriving animals of their liberty or subjecting them to pain or discomfort, to meet a human need or value.

At an extreme end of the ethics spectrum is the claim that all animals have rights equal to humans, and therefore any experiment that wouldn't ethically be conducted on humans shouldn't be conducted on any animal.

Ethics boards today tend to weigh up the potential benefits of an experiment with the risks of harm and suffering to the animal. However, what constitutes a benefit , as well as objective ways to define acceptable limits of harm, pain, and discomfort in different animals can make this more challenging than first appears.

What is the future of animal testing?

More than half a century ago, zoologists William Russell and Rex Burch suggested experimentation should become more humane by following the three Rs; restrict when to use animals; refine the kinds of experiments conducted on them; and replace as the technology becomes available.

Advances in computer modelling and in-vitro tissue culture design are continuing to provide alternatives to animal models that don't suffer from the same ethical and practical limitations.

Human tissue models, such as those making up 3D tissue conglomerates called organoids , are increasingly serving as appropriate models for studying growth and development.

These solutions might not make the way we conduct the experiments themselves more trustworthy. But with robust debate and reliable review procedures, they will steadily make animal testing - and the ethical and practical problems they bring - a thing of the past.

All Explainers are determined by fact checkers to be correct and relevant at the time of publishing. Text and images may be altered, removed, or added to as an editorial decision to keep information current.

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Animal testing and experiments FAQ

How many animals are used in experiments each year?

Which animals are used in experiments, what kinds of experiments are animals used in, what kinds of institutions use animals in experiments, where do laboratories get the animals they use in experiments, what is life like for animals in laboratories, what happens to the animals once an experiment is over, aren’t there laws to protect animals used in experiments, why are animals still used in experiments, what are the alternatives to experiments on animals, what are the advantages of using non-animal alternatives instead of animals in experiments.

• What are you doing to end experiments on animals?

What can I do to help animals in laboratories?

Stand with us to demand that the federal government, state governments, companies and universities stop relying on outdated animal experiments.

It is estimated that more than 50 million animals are used in experiments each year in the United States. Unfortunately, no accurate figures are available to determine precisely how many animals are used in experiments in the U.S. or worldwide.

The U.S. Department of Agriculture (USDA) does compile annual statistics on some animals used in experiments, including cats , dogs , guinea pigs , hamsters , pigs , primates , rabbits and  sheep .

However, the animals most commonly used in experiments—“purpose-bred” mice and rats  (mice and rats bred specifically to be used in experiments)—are not counted in annual USDA statistics and are not afforded the minimal protections provided by the Animal Welfare Act. The Animal Welfare Act is a federal law that sets minimal standards for the treatment of certain warm-blooded animals used in experiments. The law also requires that unannounced inspections of all regulated animal testing facilities are carried out annually, although some facilities only receive partial inspections . In addition to purpose-bred mice and rats, animals such as crabs, fish , frogs, octopuses and turtles , as well as purpose-bred birds , are not covered by the Animal Welfare Act. The failure to protect these animals under the law means that there is no oversight or scrutiny of their treatment in the laboratory or the experiments performed on them. And, because these animals are not counted, no one knows how many of them are suffering in laboratories. It also means that facilities using unprotected species in experiments are not required to search for alternative, non-animal methods that could be used to replace or reduce harmful experiments that use animals.

View Animals Used in Experiments by State

View Dogs Used in Experiments by State

Read Dogs Used in Experiments FAQ

Use our Animal Laboratory Search Tool  to find information about universities, hospitals, companies and other organizations that use certain animals in experiments

View a list of U.S. laboratories that use certain animals in experiments ; click on “License Type” and select “Class R – Research Facilities." Note that numbers only include animals covered by the Animal Welfare Act.

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Animals used in experiments include baboons, cats , cows , dogs , ferrets,  fish , frogs, guinea pigs , hamsters , horses , llamas, mice , monkeys (such as marmosets and macaques), owls, pigs , quail, rabbits , rats and  sheep .

Chimpanzees have thankfully not been subjected to invasive experiments in the U.S. since 2015, when federal decisions were made to prevent their use. Despite this, hundreds of chimpanzees are still languishing in laboratories while they wait to be moved to sanctuaries.

Animals are used in many different kinds of experiments. These are just a few examples:

• Dogs have their hearts, lungs or kidneys deliberately damaged or removed to study how experimental substances might affect human organ function.  
• Monkeys are taken from their mothers as infants to study how extreme stress might affect human behavior.
• Mice are force-fed daily doses of a chemical for two years to see if it might cause cancer in humans.
• Cats have their spinal cords damaged and are forced to run on treadmills to study how nerve activity might affect human limb movement.
• Ferrets are deliberately infected with extremely painful, potentially fatal diseases (such as RSV, COVID-19 or Ebola) and not given pain relief or treatment before their death to study how humans might be affected by the same disease.  
• Pigs are implanted with various devices (such as pacemakers and dental implants) to study how human bodies might respond to such devices.  
• Pregnant rabbits are force-fed toxic pesticides every day for several weeks to study how human mothers and babies might be affected if they were exposed to the pesticides.
• Sheep are subjected to high pressures (such as those experienced deep underwater) for hours at a time and then returned to normal pressure so that their response can be observed.
• Rats are placed in small tubes and are forced to inhale cigarette smoke for hours at a time to study how humans might respond to cigarette smoke.   
• Baboons are injected with endometrial tissue to induce painful symptoms of endometriosis and study how humans might be affected by the disorder.
• Horses are infected with a potentially fatal virus (such as hepatitis) and their symptoms monitored to study how humans might be affected by the same virus.

Experiments are often excruciatingly painful for the animals used and can vary in duration from days to months to years. The experiment can cause vomiting, diarrhea, irritation, rashes, bleeding, loss of appetite, weight loss, convulsions, respiratory distress, salivation, paralysis, lethargy, bleeding, organ abnormalities, tumors, heart failure, liver disease, cancer and death.

There is no limit to the extent of pain and suffering that can be inflicted on animals during experiments. In some instances, animals are not given any kind of pain medication to help relieve their suffering or distress during or after the experiment on the basis that it could affect the experiment.

Animals are typically killed once an experiment is over so that their tissues and organs can be examined, although it is not unusual for animals to be used in multiple experiments over many years. There are no accurate statistics available on how many animals are killed in laboratories every year.

Read Cosmetics Animal Testing FAQ

• Read about our 2022 undercover investigation at Indiana laboratory Inotiv, one of America’s largest animal testing labs. We documented hundreds of dogs, monkeys, rats and pigs undergoing experiments, including terrified beagle puppies being force-fed a potentially toxic drug in cruel and ineffective months-long tests paid for by Crinetics, a pharmaceutical company in San Diego.
• Read about our 2019 undercover investigation at a Michigan laboratory where thousands of dogs are killed every year. After weeks of pressure from the public, the pesticide company that had commissioned a year-long fungicide test on 32 dogs agreed that the test was unnecessary and released the dogs to one of our shelter partners to be adopted.

Chemical, pesticide and drug companies (as well as contract laboratories that carry out tests for those companies), public and private universities, community and technical schools, government facilities, Veterans Affairs (VA) facilities and hospitals all use animals in experiments.

View Chart of Institutions That Use Dogs in Experiments

The majority of animals in laboratories are “purpose-bred” meaning that they are bred specifically to be used in experiments. People who breed and sell certain purpose-bred animals are called Class A dealers and are licensed and inspected by the U.S. Department of Agriculture (USDA). Facilities that only sell purpose-bred mice, rats, birds or cold-blooded animals such as crabs, fish, frogs, octopuses and turtles to laboratories are excluded and are not licensed or inspected by the USDA.

Some animals used in experiments are taken from the wild—including birds and  monkeys . 

Historically, some cats and dogs  were sold to laboratories by brokers known as random source Class B dealers, who acquired animals at auctions, from newspaper ads and various other sources, including animal shelters. Random source Class B dealers have not been allowed to operate since 2015 when Congress first passed legislation to prevent them from being licensed.  

Some cats and dogs in laboratories are still obtained directly from animal shelters, a practice known as “pound seizure.” Pound seizure laws vary from state to state with one state (Oklahoma) requiring shelters to give cats and dogs to laboratories, rather than euthanizing them, and others allowing or prohibiting laboratories from taking animals from animal shelters. Some states have no laws at all, leaving it up to the individual shelter or locality.

View Pound Seizure Laws by State

Animals in laboratories suffer immensely. In addition to the painful experiments that the vast majority of animals in laboratories experience over days, months, years or even decades, life in a laboratory is typically a miserable and terrifying experience.

Typically kept alone in barren steel cages with little room to move around and few, if any, comforts, such as toys or soft bedding, animals often become excruciatingly lonelyand anxious, often devoid of the companionship of other animals or the loving touch of a human. Animals in laboratories can associate humans with painful situations and, with no way to hide or get away, they panic whenever a person approaches their cage or freeze with fear when they are taken into treatment rooms. Despite this, dogswill often still seek out human attention.

Animals in laboratories typically also have to watch (or hear) other animals suffering, including their own parents, siblings or babies. High levels of constant stress can cause animals to exhibit unnatural behaviors. For example, it is not uncommon for monkeys to mutilate themselves or to rock or vocalize constantly as a way to help relieve their anxiety, mice to overgroom each other until they are completely bald, and dogs to continually pace.  

Very often the experiments themselves lead to suffering and death. In our 2022 undercover investigation we documented monkeys in “restraint chairs”—devices that are used to hold monkeys in place while the experiments are carried out—who accidentally hanged themselves while unattended. We also documented a dog named Riley used to test a substance so toxic that it brought him near death after only two days of forced dosing. He was hypersalivating, trembling, vomiting, and moaning, yet was dosed yet again with this highly toxic substance. Later, he lay on the floor, unable to stand. Our undercover investigator tried to comfort him while he was dying, but Riley was left to suffer in excruciating pain overnight because the laboratory’s veterinarian was unavailable on a weekend

Animals in laboratories are also subject to mistreatment by inexperienced or careless staff. Although there are penalties for laboratories when animals are injured or killed due to negligence or when they fail to meet minimum standards of animal care, in reality, the fines are typically either very small or waived entirely.

In some cases, animals die as a deliberate result of the experiment. For example, the LD50 (lethal dose 50%) test, which is typically performed on mice, rats, pigeons, quail and fish, involves determining the dose of a substance (such as a pesticide) that kills (or would lead to the death of) 50% of the animals tested.

It is extremely rare that animals are either adopted out or placed into a sanctuary after research is conducted on them. However, more and more states are passing laws that require laboratories, when possible, to offer dogs and cats to shelters and other rescue organizations so they can be adopted into loving homes after the experiments they were used in have ended. As of December 2023, 16 states have such laws.

The Animal Welfare Act was designed to protect certain animals, like dogs and monkeys, used in experiments, but the law only offers minimal standards for housing, food and exercise. The Animal Welfare Act also stipulates that the proposed experiments be reviewed by an Institutional Animal Care and Use Committee, whose members are appointed by the laboratory itself and largely made up of employees of the institution. A 2014 audit report reviewing Animal Welfare Act oversight of laboratories found that “animals are not always receiving basic humane care and treatment and, in some cases, pain and distress are not minimized during and after experimental procedures.”

The animals most commonly used in experiments—“purpose-bred” mice and rats  (mice and rats bred specifically to be used in experiments)—are not counted in annual USDA statistics and are not afforded the minimal protections provided under the Animal Welfare Act. The Animal Welfare Act is a federal law that sets minimal standards for the treatment of certain warm-blooded animals used in experiments. The law also requires that unannounced inspections of all regulated research facilities are carried out annually. In addition to purpose-bred mice and rats, animals such as crabs, fish , frogs, octopuses and turtles as well as purpose-bred birds are not covered by the Animal Welfare Act. The failure to protect these animals under the law means that there is no oversight or scrutiny of their treatment and use in the laboratory. And, because these animals are not counted, no one knows how many of them are suffering in laboratories. It also means that facilities using unprotected species in experiments are not required to search for alternative, non-animal methods that could be used to replace or reduce harmful experiments that use animals.

The vast majority of experiments on animals are not required by government law or regulations. Despite that, government agencies often seem to prefer that companies carry out animal tests to assess the toxicity or efficacy of products such as industrial chemicals, pesticides, medical devices and medicines.

For example, the Environmental Protection Agency (EPA) requires that a new pesticide be fed to dogs for 90 days as part of its evaluation and approval process. The Food and Drug Administration (FDA), which regulates various products such as drugs, medical devices, food, fragrances and color additives, will not approve potential drugs unless they are first tested on animals, which usually includes dogs. In addition to tests on  dogs ,  mice and rats ,  rabbits ,  birds  and primates are also used to test pesticides and drugs. These types of tests have been performed for years, regardless of whether they provide valuable information. While some regulatory agencies, like the EPA, are now taking a critical look at these animal tests to determine if they provide information necessary for assessing how safe a product or substance is for humans, and if better approaches are available, others have done little. More efforts can be made by agencies to invest in and encourage the development of non-animal methods.

Swapping animal experiments for non-animal alternative methods seems like a straightforward process, given that using animals has so many limitations and sophisticated new technologies offer countless possibilities for creating methods that are more humane and that more accurately mimic how the human body will respond to drugs, chemicals or treatments. Unfortunately, developing these alternatives is a complex process facing many obstacles, including inadequate funding. In most cases, a non-animal alternative must be formally validated—historically an expensive and lengthy process—in order to be accepted by government regulatory agencies, both in the U.S. and globally, although new, faster approaches to approving these methods are being developed. In contrast, animal experiments have never been subjected to the same level of scrutiny and validation. Despite these challenges, many scientists are increasingly committed to developing and using non-animal methods.

The world is continuously moving toward a future dominated by sophisticated methods that use human cells, tissues and organs, 3D printing, robotics, computer models and other technologies to create experiments that do not rely on animals.

While many animal experiments have not changed since they were developed decades ago and will always have severe limitations, advanced non-animal methods represent the very latest techniques that science has to offer, provide countless possibilities to improve our understanding and treatment of human diseases and will only continue to improve over time. Non-animal methods also have several advantages over outdated animal experiments: they more closely mimic how the human body responds to drugs, chemicals and treatments; they are more efficient and often less expensive; and they are more humane. Ultimately, moving away from animal experiments is better for both humans and animals.

We advocate for the immediate replacement of animal experiments with available non-animal methods and for more funding to develop new non-animal methods. A concerted effort to shift funding and technological development toward more non-animal alternatives will lead us to a future where animal experiments are a thing of the past.

Examples of non-animal alternative methods

• “Organs-on-chips” are tiny 3D chips created from human cells that look and function like miniature human organs. Organs-on-chips are used to determine how human systems respond to different drugs or chemicals and to find out exactly what happens during infection or disease. Several organs, representing heart, liver, lungs or kidneys, for example, can be linked together through a “microfluidic” circulatory system to create an integrated “human-on-a-chip” model that lets researchers assess multi-organ responses.
• Sophisticated computer models use existing information (instead of carrying out more animal tests) to predict how a medicine or chemical, such as drain cleaner or lawn fertilizer, might affect a human.
• Cells from a cancer patient’s tumor are used to test different drugs and dosages to get exactly the right treatment for that specific individual, rather than testing the drugs on animals.
• Specialized computers use human cells to print 3D tissues that are used to test drugs.
• Skin cells from patients, such as those with Alzheimer’s disease, are turned into other types of cells (brain, heart, lung, etc.) in the laboratory and used to test new treatments.
• Sophisticated computer programming, combined with 3D imaging, is used to develop highly accurate 3D models of human organs, such as the heart. Researchers then input real-world data from healthy people and those with heart disease to make the model hearts “beat” and test how they might respond to new drugs.

Human cells or synthetic alternatives can replace horseshoe crab blood in tests to determine whether bacterial contaminants are present in vaccines or injectable drugs.

• Animal experiments are time-consuming and expensive.
• Animal experiments don’t accurately mimic how the human body and human diseases respond to drugs, chemicals or treatments.
• Animals are very different from humans and, therefore, react differently.
• Increasing numbers of people find animal testing unethical.
• There are many diseases that humans get that animals do not.

What are you doing to end experiments on animals?

We advocate for replacing animals with non-animal alternative methods when they are available and more funding for the development of new alternative methods to quickly replace antiquated and unreliable animal tests and experiments. Our two main areas of focus are ending cosmetics animal testing  and ending experiments on dogs .

Cosmetics testing on animals

We—along with our partner, Humane Society International —are committed to ending cosmetics animal testing forever. Through our  Be Cruelty-Free campaign, we are working in the United States and around the globe to create a world where animals no longer have to suffer to produce lipstick and shampoo. 

• In the United States, we are working to pass the Humane Cosmetics Act , federal legislation that would prohibit animal testing for cosmetics, as well as the sale of animal-tested cosmetics.
• We are also working in several U.S. states to pass legislation that would end cosmetics animal testing. As of March 2024, 12 states (California, Hawai'i, Illinois, Louisiana, Maine, Maryland, Nevada, New Jersey, New York, Oregon, Virginia and Washington) have passed laws banning the sale of animal-tested cosmetics.
• Internationally, as of December 2023, 45 countries have passed laws or regulations to ban cosmetics animal testing, including every country in the European Union, Australia, Brazil, Canada, Chile, Colombia, Ecuador, Guatemala, Iceland, India, Israel, Mexico, New Zealand, Norway, South Korea, Switzerland, Taiwan, Turkey, the United Kingdom.
• We work with scientists from universities, private companies and government agencies around the globe to promote the development, use and regulatory acceptance of non-animal test methods that will reach beyond cosmetics.
• We educate consumers about animals used in cruel and unnecessary cosmetics tests and how to shop for cruelty-free cosmetics and personal care products.

Experiments on dogs

There is no place for harmful experiments on dogs in the U.S. We are committed to ending this practice.

• In the summer of 2022, we led the removal of 3,776 beagles from Envigo, a facility in Virginia that bred dogs to sell to animal laboratories. This historic mission was the result of a lawsuit filed by the U.S. Department of Justice that described shocking violations of the Animal Welfare Act at the facility. Instead of continuing to suffer, the dogs were removed from Envigo and headed to loving homes , a process facilitated by our shelter and rescue partners around the country.
• In April 2022, we released the results of our undercover investigation at Inotiv, an Indiana laboratory where thousands of dogs, monkeys, pigs and rats are used in experiments and killed.
• In 2021, we released a report examining the U.S. government’s role in using dogs in experiments. We found that the government uses millions of taxpayer dollars to fund harmful experiments on dogs each year—and also seems to prefer that companies carry out dog tests. Our researchers scrutinized public records and found that between 2015 and 2019, the National Institutes of Health (NIH) awarded more than $200 million to 200 institutions for 303 projects that used dogs in harmful experiments. Dogs were subjected to multiple surgeries, fitted with equipment to impair their heart function and implanted with devices to alter normal bodily functions. Following the conclusion of an experiment, dogs are typically killed instead of being adopted into loving homes.
• In 2019, we released the results of our undercover investigation at a Michigan laboratory where thousands of dogs are killed every year. After weeks of pressure from the public, the pesticide company that had commissioned a test year-long fungicide test on 32 dogs, agreed that the test was unnecessary and released the dogs to one of our shelter partners so they could be adopted.
• After a recent analysis we performed that showed the 90-day dog test for pesticide registration was rarely used by the Environmental Protection Agency (EPA) to assess the risk that pesticides pose to humans, we are urging the agency to eliminate or significantly limit this test in the near future. We also want the agency to reaffirm their previously stated commitment to end their reliance on using mammals to test pesticides and chemicals by 2035.
• We are asking the Food and Drug Administration (FDA) to support the development of alternative methods that replace dogs in experiments. 
• We want the Department of Veterans Affairs (VA) to adopt the recommendations of an independent panel review released in 2020 that analyzed VA experiments using dogs, identified several areas where dogs are not needed and urged the agency to develop a strategy to replace all animal use. 
• We are recommending that the National Institutes of Health (NIH) scrutinize grant proposals for projects using dogs, by applying strict criteria that must be met before dogs can be used and that they ban the use of dogs in experiments that cause unrelieved pain. We are also requesting that the NIH define a date when they will no longer fund or support experiments on dogs.
• prohibit or limit the use of dogs in experiments not required by federal law, similar to laws passed in California and Illinois .
• ensure an opportunity for  dogs and cats to be adopted into loving homes after the experiment ends.
• strengthen regulatory oversight of facilities that breed dogs destined for laboratories and increase penalties for animal welfare violations.
• Direct state funding to support the research and development of modern non-animal technologies, similar to the law passed in Maryland .

One easy way to help animals suffering in cosmetics tests is to swap out your personal care and household products for cruelty-free versions! Cosmetics (such as shampoo, deodorant and lipstick) and household products (such as dish soap, laundry detergent and glass cleaner) are typically tested on guinea pigs , rabbits ,  mice and rats .

Help us demand better for animals used in experiments through the following actions:

• Tell the FDA to stop encouraging companies to test on animals and instead switch to sophisticated non-animal alternatives.
• Stand with us to end research and tests on dogs by signing our petition.
• Urge the USDA to do their job and help protect animals in laboratories.
• Ask your federal legislators in Congress to ban cosmetic tests on animals.
• Support efforts to replace animal experiments with advanced non-animal alternatives that are better for both human health and animal welfare.

Follow us on Facebook to learn the latest news and actions related to animals in laboratories!

Alternatives to horseshoe crab blood

The Humane Society of the United States urges that horseshoe crab blood be replaced with non-animal methods when conducting endotoxin tests for medical products.

Vaccine, injectable drug and medical device manufacturers must test for endotoxins, a type of bacterial contaminant that, if present, can cause patients to develop symptoms that can include fever, chills, headache and nausea. Blood from horseshoe crabs is used to conduct the Limulus amebocyte lysate (or LAL) test for endotoxins.

The problem

To create this test, horseshoe crabs are captured from the wild and up to 30% of their blood is removed by medical supply companies. The crabs are later returned to the wild; however, it is estimated that 10-15% or more of them die as a result of this process.

In addition to being collected for their blood, horseshoe crabs are gathered up by fisheries, which use them as bait. These practices have led to a rapid decrease in the horseshoe crab population, putting them at risk of extinction. The decrease in wild horseshoe crab populations also impacts other species, including migratory shorebirds like the red knot, a threatened species that depends on horseshoe crab eggs for food.

THE solution

Scientists have developed recombinant Factor C (rFC), a synthetic alternative to the protein in horseshoe crab blood that can detect bacterial endotoxins. Repeated studies have demonstrated that rFC is equivalent or superior to the LAL test. A second method—the monocyte activation test—uses human cells and can not only detect bacterial endotoxins, but also pyrogenic (fever-causing) non-endotoxins.

what should be done

As a member of the Horseshoe Crab Recovery Coalition, the Humane Society of the United States is advocating for the replacement of the Limulus amebocyte lysate test with recombinant Factor C (rFC) or the monocyte activation test (MAT).

We urge the U.S. Pharmacopoeia—which sets quality, purity, strength and identity standards for medicines, food ingredients and dietary supplements—to encourage manufacturers to use rFC or MAT rather than LAL.

We also urge the U.S. Food and Drug Administration to update its guidance for vaccine, injectable drug and device manufacturers to indicate that these non-animal tests are now the preferred methods for endotoxin and pyrogenicity testing.

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• Academia - Disputed discovery: vivisection and experiment in the 19th century
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vivisection , operation on a living animal for experimental rather than healing purposes; more broadly, all experimentation on live animals. It is opposed by many as cruelty and supported by others on the ground that it advances medicine; a middle position is to oppose unnecessarily cruel practices, use alternatives when possible, and restrict experiments to necessary medical research (as opposed, for example, to cosmetics testing). Surgery on animals without anesthesia was once common; many people, most significantly René Descartes , claimed that animals did not really feel pain . The testing of certain chemicals on animals to find the lethal dose still occurs; however, the development of alternative methods (computer simulations, tissue culture tests) has led some funding agencies and research organizations to ban these tests. An antivivisection movement in the late 19th century broadened its scope to include prevention of all cruelty to animals and later gave rise to the animal rights movement.

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Why We Still Test on Animals, Explained

A fraught regulatory environment and human stubbornness help explain the roadblocks.

Explainer • Research • Science

Words by Marlena Williams

In a bustling laboratory at the Harvard Stem Cell Institute, hundreds of scientists are busy creating self-organizing, three-dimensional tissue cultures known as organoids out of stem cells. These tiny cell cultures, ranging in size from the width of a hair to five millimeters, are capable of replicating the complexity of real human organs. In practical terms, scientists can — and already are — replicating human kidneys, brains, lungs, intestines, stomachs and livers. The technology offers us a huge opportunity to shift the way we test drugs, foods and cosmetic products. Scaled up, organoids could also eliminate the need to use animals in research and testing . By replicating the complexity and specificity of human organs, organoids offer an accurate, cost-effective and humane alternative to using animal models, so why aren’t we using them?

Organoids aren’t the only promising alternative on the horizon. From organs-on-chips — 3D devices that look and function like human organs — to highly sophisticated computer modeling systems , there are more alternatives to animal testing today than ever before.

And yet laboratory animals remain the dominant means by which we test products, with more than 115 million animals tested annually , to develop new drugs and study both human and animal diseases. While animal testing has certainly helped to usher in many life-saving medical and scientific advancements over the years — including the discovery of penicillin and the development of the polio vaccine — it comes with its own unique set of limitations and concerns.

Animals respond differently to drugs and stimuli than humans, especially when confined in the highly artificial and stressful environment of a lab, and testing on animals often creates unreliable and hard-to-replicate results. About 90 percent of drugs fail once they reach the human clinical trial stage. There are a variety of reasons why this happens, researchers say, including the fact that medicines function differently in the cells of one of the most common lab animals, mice , as compared to humans.

Animal testing is also expensive. The estimated dollar costs to bring a drug to market could be as much as $1 billion, give or take, to more than $2 billion in total, and for cancer drugs, can take more than a decade to hit the market .

So why are we still using laboratory animals, especially when so many other promising alternatives exist? This remains an incredibly fraught and complicated question, one that has divided scientists, animal advocates and even most Americans , for centuries.

Animal Testing: An Overview

There is no one definitive type of animal testing . Animals are tested on in a wide variety of ways, in a wide variety of settings, for a wide variety of reasons.

Scientific and medical researchers use animals to develop new drugs and vaccines, study biological systems and to advance new surgical procedures and treatment methods. Many commercial industries use laboratory animals to test the safety of their cosmetics, household cleaners, food additives, pesticides, chemicals and other potentially harmful substances, either by conducting the tests themselves or by contracting with third party companies.

Laboratory animals are also used in the classroom , in the military and even in outer space .

While there is no definitive number of how many animals are used in total in research and testing, it is estimated that more than 50 million laboratory animals are used in the United States each year. Rats and mice make up 85-95% of animal research subjects here, but dogs, monkeys, rabbits, guinea pigs, fish and birds are also widely used across many industries.

Until the 1960s, there were no federal laws regulating animal research or setting standards for laboratory animal welfare. With no federal oversight, the animal testing world was a sort of wild west , where researchers obtained their animal subjects from questionable sources — like unlicensed dealers and overcrowded animal shelters — and held them in often deplorable facilities, conducting a variety of cruel and unnecessary experiments and procedures on them without anesthesia or other pain management interventions.

The Animal Welfare Act was passed in 1966, largely in response to a disturbing story of a Dalmatian named Pepper who was stolen from her family home in Pennsylvania by an unscrupulous dealer and sold to a hospital in New York, where she was experimented on, killed and then incinerated. Pepper’s story — along with a sensational Life magazine article on dog dealers titled “ Concentration Camps for Dogs ” — spurred the welfare act’s passage and ushered in long overdue welfare protections for laboratory animals, including minimum standards for humane care, a registration system for testing facilities and a clear ban on the use of stolen animals in experiments.

A strategy known as the 3 R’s —  short for Replacement, Reduction, and Refinement — quickly became the guiding principles for humane animal experimentation in the twentieth century, and remain so to this day. The idea is to reduce the number of animals used in testing and improve animal welfare conditions as much as possible.

The Animal Welfare Act — amended in 1985 to make research facilities more accountable — and the Health Research Extension Act that followed were designed to minimize the pain and stress experienced by laboratory animals, not to completely eliminate their use or explore non-animal alternatives.

Legal scholar and animal ethicist Paul Locke argues that the “keys to the laboratory” remain firmly in the hands of researchers . These scientists have little oversight and only have to report the most egregious failures and abuses to federal authorities. What’s more, any researchers who want to treat animals more humanely are often hamstrung by institutional practice, career pressures and a general culture that views animal testing as a “necessary evil.”

Proponents of animal testing often argue that animal models are justified because the benefits to humans outweigh concerns about animal suffering. But as more testing alternatives emerge, the reasons for sticking with animals begin to dwindle. At this point, there are countless technological advancements that could make both human and animal subjects unnecessary.

But despite the promise of these non-animal models, many institutions and researchers cling to the status quo —in part out of a resistance to change, but also a lack of real investment in proven alternatives and political tensions within competing movements.

“The American Chamber of Horrors”

In 1933, one woman died and more than a dozen others were blinded after using a permanent mascara and eyebrow dye called Lash Lure , which contained an untested chemical derived from coal tar called p-phenylenediamine. Lash Lure caused painful blisters, abscesses and ulcers in and around the eyes of its unsuspecting consumers, some of whom were photographed and featured in a display at the 1933 Chicago World Fair that one journalist referred to as “ The American Chamber of Horrors .”

Just a few years later, 107 people, mostly children, died after ingesting the anti-bacterial drug Elixir Sulfanilamide , which contained a sweet-tasting ingredient also found in antifreeze.

The public outcry following the Lash Lure and Elixir Sulfanilamide tragedies prompted Congress to pass the Food, Drug and Cosmetic Act in 1938, the first law in the country to regulate the steadily growing pharmaceutical and cosmetics industries. The FDCA required cosmetics manufacturers to submit evidence of a product’s safety and effectiveness before marketing it to the general public. Animal testing quickly became the default way for cosmetics companies to ensure the safety of their products and to potentially avoid criminal liability for placing a harmful product on the market. Though the original FDCA didn’t require animal testing for cosmetics like it did for drugs, the agency still highly encouraged companies to test their products on animals.

One of the most common cosmetics testing methods involved “acute ocular toxicity,” or Draize, tests , named after the FDA scientist who invented the method in the 1940s. These tests involved restraining a conscious, unanesthetized rabbit and applying the chemical or product directly to its eyes. The substance was left on the eyeball for a set period of time, and the animal was then monitored for up to 14 days for signs of redness, swelling, hemorrhaging or irritation.

Draize tests remained the gold standard for FDCA compliance until a highly visible campaign, led by activist Henry Spira, drew attention to the tests in the 1980s. Spira ran an ad in the New York Times showing a blind laboratory bunny beneath the headline, “How many rabbits does Revlon blind for beauty’s sake?” The ad and resulting campaign brought increased attention to the cruelty of animal testing and prompted many brands to start searching for alternatives.

But cosmetics testing remains common , even in the 21st century. When companies choose to develop or use new ingredients in their products, they may still decide to conduct tests on animals to assess the safety of the product. No one wants to be responsible for another Lash Lure tragedy. Such tests, however, are now completely unnecessary: the FDCA does not explicitly require animal testing for cosmetics — only clearly demonstrated safety — and there are already thousands of ingredients available that have proven histories of safe and effective use.

By far the biggest factor keeping companies from going fully cruelty-free is China, which long required all cosmetics that entered its borders to be tested on animals. Though China has recently amended its regulations to exempt some imported products from mandatory testing, the country still requires animal testing for many popular cosmetics. Beauty companies that want to sell into the massive Chinese market–which accounted for a whopping $88 billion dollar sales in 2021 alone—must allow their products to be tested on animals.

While many cosmetics companies have decided to maintain their cruelty-free status and not sell or market their products in China, some of the biggest beauty companies like Revlon and L’Oreal, which in turn own dozens of other smaller beauty companies, do sell there. Though these companies will often adamantly deny using animal testing, they often do allow animal testing when required by law , likely meaning in China.

But the law elsewhere in the world is rapidly changing. The European Union banned cosmetics testing in 2013 , and dozens of other countries, including Mexico, Canada, Australia and India, quickly followed suit. Though there is currently no federal law in the United States banning cosmetics testing outright, twelve U.S states prohibit the sale of products tested on animals within their borders.

Unlikely Allies and Foes

Voters and consumers are understandably horrified by the idea of rubbing hairspray or perfume into the eyes of helpless white rabbits just so we can defrizz our hair or smell a little better. But making political and social progress on other forms of animal testing is a far more difficult task. When it comes to toxicity testing , progress towards alternative methods has long been delayed by an often surprising web of conflicts between environmentalists, animal advocates, government agencies and polluting corporations.

Take, for example, the case of the Environmental Protection Agency. In September 2019, Andrew Wheeler, the head of the EPA under Donald Trump, announced that the agency would reduce animal toxicity tests by 30 percent by 2025 and stop these experiments altogether by 2035.

Under the Toxic Substances Control Act , the EPA is empowered to conduct and oversee a massive amount of animal testing — involving anywhere from 20,000 to 100,000 animals annually —in order to determine the effects of certain chemicals or pollutants on fertility, development, genetics and overall health. These tests often involve pumping chemicals straight into an animal’s stomach or forcing animals to inhale potentially lethal chemicals in a gas chamber.

The Food, Drug and Cosmetics Act further authorizes the EPA to regulate pesticides . When registering a new pesticide, the EPA requires companies to perform a 90-day oral toxicity study on both rodent and non-rodent species — typically cats and dogs —as part of its human health risk assessment. A 2019 undercover investigation by the Humane Society of the United States revealed dozens of beagles being force-fed varying doses of pesticides at a Dow AgroSciences facility in order to test their toxicity as required by the EPA.

But Wheeler’s decision to roll back animal testing requirements was immediately criticized by people within the environmental movement, who accused the administrator of bowing to pressure from the powerful chemical industry . Chemical giants like Dow and DuPont tend to balk at such testing because it is both time-consuming and expensive.

While Wheeler maintained that his decision was based out of his love for animals, it wasn’t a logical jump to assume that the Trump administration was favoring polluting industries over the health of American citizens and the environment. Major environmental groups like the National Resources Defense Counsel have since come out in support of animal toxicity tests .

These debates show the political thorniness of the toxicity testing debate, which pits environmental groups against the agency tasked with protecting the environment, and aligns animal advocates with the conservatives and big businesses they often oppose.

While animal toxicity tests may prevent potentially dangerous chemicals from harming people, other animals and the environment, these tests are less fool-proof than the agency’s reliance on them might suggest. One study found oral toxicity testing on dogs to be an unnecessary step , and another showed that rodent models accurately predicted human toxicity in only 43 percent of cases. Lethal dose tests, whereby animals are forced to swallow large amounts of chemicals to determine the amount that causes death, are considered impractical, as most humans are exposed to these harmful substances at far slower rates and in far smaller doses.

The National Academy of the Sciences has been urging a shift away from animal testing since 2007. Thanks to a grant from the EPA, scientists at Johns Hopkins have been working to develop lab grown “mini-brains” that may enable researchers to study neurotoxic effects without the need for animal subjects. Even simple changes, like improving the searchability of the EPA’s current testing data , could dramatically reduce the need to test chemicals and pesticides on animals.

But in another twist, it now seems that under the Biden administration, the EPA has scrapped its plans to eliminate animal testing , instead opting for the vague goal of reducing reliance on animal models and researching viable alternatives.

New non-animal models will require rigorous regulatory approval before they are accepted, and even proponents of these alternatives think they are still a long way off from becoming the norm. A potent mix of government inertia, political volatility and public skepticism towards new methods may favor the status quo over more humane and effective alternatives.

Cures vs. Creatures

The toxicity debates look tame compared to the contentious, often ugly debates that have been raging between animal advocates and the medical and scientific community since at least the 19th century.

Professor Paul Locke calls this the “cures vs. creatures” dilemma. On the one hand, there is deep societal respect and need for the doctors and scientists who rely on animal models to better understand human biology, cure horrible diseases and prevent future harms.

But on the other hand, there is an equally strong societal force that believes animals are sentient creatures deserving of protections and rights. Animal advocates find something deeply hypocritical about a research model that uses animal subjects because of their similarity to humans while refusing to acknowledge that these creatures are capable of many of the same emotions and sensations as us.

“To avoid seeing this double treatment as a problem, and thus to avoid ethical reflection on it, requires an extraordinary level of self-deception, rationalization, and selective blindness,” writes scientist John Gluck in his book, Voracious Science and Vulnerable Animals . “It requires [researchers] to objectify experimental animals, categorically excluding them from the class of beings requiring full ethical considerations.”

Both sides of the “cures vs. creatures” dilemma deploy rousing narratives and imagery to prove the nobility of their cause. Animal activists can shock and horrify with nightmarish stories about the thousands of dogs , cats , monkeys and rodents who suffer in labs, while doctors and researchers can comfort and inspire with stories of the life-saving medical advancements that have benefited from animal testing, from the cure for smallpox to the COVID-19 vaccine . But these competing narratives can help to keep the animal testing debate polarized and forestall any effective progress towards widely available non-animal alternatives that could both eliminate animal suffering and offer more accurate, reliable and cost-effective results.

Scholars and animal advocates like Paul Locke believe that animal models will be needed as medical and scientific tools until enough money is pumped into the system to support and vet non-animal alternatives. While technologies like organoids, organs-on-chips and computer simulations show great promise for future advancements, there has not been enough institutional interest or investment in these alternatives to make a meaningful difference in transforming the current system.

In 2023, President Biden signed into law an amendment to the FDCA removing the requirement that pharmaceutical companies test their drugs on animals before moving on to human clinical trials. Testing is no longer required, but it may still be encouraged by the agency if they believe it is useful or necessary. Last year’s federal budget also included $5 million dollars for a new FDA program designed to develop and encourage non-animal testing methods.

But $5 million dollars is a mere drop in the bucket of the FDA’s massive $8.4 billion federal budget and is hardly enough to support the large-scale institutional shift that will be necessary to replace animal testing with non-animal alternatives. If the National Institute of Health invested just 1 percent of its whopping $48 billion dollar budget in exploring non-animal alternatives, for example, we could make significant progress towards shifting away from animal testing, at least when it comes to scientific and medical research.

The Bottom Line

Laboratory animals receive certain minimal welfare protections under the law, but they continue to be used by the millions for research testing for a wide range of industries — from food to fashion to biomedical research — despite the alternatives.

For researchers to shift to using these new methods, we may just need to, as scientist John Gluck writes , “rethink and re-form the entire framework of beliefs that underlies our relationship with nonhuman species.” But that kind of rethinking will require a serious national conversation about the place of animals in society, and how they should be treated and perceived, in the laboratory and beyond.

Independent Journalism Needs You

Marlena Williams is a writer from Portland, Oregon. She is the author of the essay collection Night Mother: A Personal and Cultural History of the Exorcist.

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Animal experimentation

Nonhuman animals are used in laboratories for a number of purposes. Examples of animal experimentation include product testing, use of animals as research models and as educational tools. Within each of these categories, there are also many different purposes for which they are used. For instance, some are used as tools for military or biomedical research; some to test cosmetics and household cleaning products, and some are used in class dissection to teach teenagers the anatomy of frogs or to have a subject for a Ph.D. dissertation.

The number of animals used in animal experimentation is certainly smaller than that of those used in others such as animal farming or the fishing industry. 1  Yet it has been estimated to be well above 100 million animals who are used every year. 2

The ways in which these animals can be harmed in experimental procedures, also known as vivisection, 3 vary. In almost all cases they are very significant and the majority of them end with the death of the animals.

There’s an important difference today between the consideration that is afforded to the potential and actual subjects used in experiments, depending on whether they are human or nonhuman animals. Few people today would condone experimenting on human beings in harmful ways, and in fact, indicative of this, such research is strongly restricted by law, when it isn’t just prohibited outright. When experimentation on humans is permitted it is always in a context of the individuals involved consenting to it, for whatever personal benefit that serves as an incentive for them. For nonhuman animals, this is not the case.

This is not because of any belief that experimentation on humans could not bring about important knowledge (in fact, it seems obvious that this practice would uncover far more useful and relevant knowledge than any experimentation on nonhuman animals ever can). Rather, the reason for this double standard is that nonhuman animals are not morally taken into account because the strong arguments against speciesism are not considered.

In the following sections the most important areas in which nonhuman animals are used in laboratories or classrooms, as well as the research methods that don’t use them, are addressed.

Animals used for experimentation

Environmental research.

Animals are made to suffer and are killed to test the impact that chemicals can have in the environment. Some of the most important environmentalist organizations have been lobbying for this practice and have often been successful despite the opposition of animal defenders.

Cosmetic and household products testing

While animal testing of new cosmetics and household products is now illegal in places such as the European Union and India, it’s still being carried out in the U.S. and other places, where many animals are blinded, caused extreme pain and killed.

Military experimentation

The use of animals to test new weaponry, bullets and warfare chemicals, as well as the effects of burns and poison for military purposes, remains mainly hidden today, but many animals die in terrible ways because of it.

Biomedical experimentation

Animals of a variety of species are harmed for numerous purposes in biomedical research because the non-animal methodologies aren’t implemented. Those animals are harmed in many ways that most people ignore.

Experimentation with new materials

When new materials are developed, they are often tested by using methods such as cell or tissue cultures, or computational models. However, materials are also commonly tested on animals who are killed afterwards.

Animals used in education

Animals used in primary and secondary education.

Dissecting animals and using them in other ways has been common practice in the U.S. and some other countries in primary and especially secondary education for many years. This means killing a huge number of animals and educating new generations in the idea that it’s acceptable to harm animals for our benefit.

Animals used in higher education

In the science departments of many different universities, research, teaching and training are successfully carried out without using animals as laboratory tools. However, animals are still subjected to all kind of procedures in many other places.

Towards a future without animals harmed in laboratories

Research methods that do not involve the use of nonhuman animals.

Defenders of animal experimentation often claim that there is no choice but to harm animals lest scientific progress be stopped, but this is not so. There are many non-harmful methods available today.

Companies that test on animals

Despite the fact that many other companies do not experiment on sentient animals, there are still companies that choose to continue carrying out animal tests out of a lack of will to implement new methods.

Companies that do not test on animals

Fortunately, although many companies today choose not to harm animals in product development, quality and safety isn’t affected in the least.

1 Every year tens of billions are killed in slaughterhouses and trillions are fished and killed in fish factories. For estimations regarding this see: Food and Agriculture Organization of the United Nations (2021) “ Livestock primary ”, FAO STAT , February 19 [accessed on 24 March 2013]. See also Mood, A. &  Brooke, P. (2010) “ Estimating the number of fish caught in global fishing each year ”, Fishcount.org.uk , July [accessed on 18 October 2020]; (2012) “ Estimating the number of farmed fish killed in global aquaculture each year ”, Fishcount.org.uk , July [accessed on 18 January 2021].

2  See Taylor, K.; Gordon, N.; Langley, G. & Higgins, W. (2008) “Estimates for worldwide laboratory animal use in 2005”,  Alternatives to Laboratory Animals , 36, pp. 327-342.

3 Although the term “vivisection” literally means “cutting a living animal,” this word has broadened its meaning in common language to denote any kind of laboratory invasive use of an animal. Defenders of animal experimentation prefer not to use it due to its negative connotations. Opponents of it claim that there shouldn’t be a problem with using this term given the meaning it already has in common language. They argue that its rejection is due to an intention to use language that is not explicit about how animals are used in this field.

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Early modern experimentation on live animals

Affiliation.

• 1 Indiana University Bloomington, Bloomington, IN, USA, [email protected].
• PMID: 22684270
• DOI: 10.1007/s10739-012-9327-7

Starting from the works by Aselli (De lactibus sive lacteis venis, 1627) on the milky veins and Harvey (1628, translated in 1993) on the motion of the heart and the circulation of the blood, the practice of vivisection witnessed a resurgence in the early modern period. I discuss some of the most notable cases in the century spanning from Aselli's work to the investigations of fluid pressure in plants and animals by Stephen Hales (Vegetable Staticks, 1727). Key figures in my study include Johannes Walaeus, Jean Pecquet, Marcello Malpighi, Reinier de Graaf, Richard Lower, Anton Nuck, and Anton de Heide. Although vivisection dates from antiquity, early modern experimenters expanded the range of practices and epistemic motivations associated with it, displaying considerable technical skills and methodological awareness about the problems associated with the animals being alive and the issue of generalizing results to humans. Many practitioners expressed great discomfort at the suffering of the animals; however, many remained convinced that their investigations were not only indispensable from an epistemic standpoint but also had potential medical applications. Early modern vivisection experiments were both extensive and sophisticated and cannot be ignored in the literature of early modern experimentation or of experimentation on living organisms across time.

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Ethical care for research animals

WHY ANIMAL RESEARCH?

The use of animals in some forms of biomedical research remains essential to the discovery of the causes, diagnoses, and treatment of disease and suffering in humans and in animals., stanford shares the public's concern for laboratory research animals..

Many people have questions about animal testing ethics and the animal testing debate. We take our responsibility for the ethical treatment of animals in medical research very seriously. At Stanford, we emphasize that the humane care of laboratory animals is essential, both ethically and scientifically.  Poor animal care is not good science. If animals are not well-treated, the science and knowledge they produce is not trustworthy and cannot be replicated, an important hallmark of the scientific method .

There are several reasons why the use of animals is critical for biomedical research: 

••  Animals are biologically very similar to humans. In fact, mice share more than 98% DNA with us!

••  Animals are susceptible to many of the same health problems as humans – cancer, diabetes, heart disease, etc.

••  With a shorter life cycle than humans, animal models can be studied throughout their whole life span and across several generations, a critical element in understanding how a disease processes and how it interacts with a whole, living biological system.

The ethics of animal experimentation

Nothing so far has been discovered that can be a substitute for the complex functions of a living, breathing, whole-organ system with pulmonary and circulatory structures like those in humans. Until such a discovery, animals must continue to play a critical role in helping researchers test potential new drugs and medical treatments for effectiveness and safety, and in identifying any undesired or dangerous side effects, such as infertility, birth defects, liver damage, toxicity, or cancer-causing potential.

U.S. federal laws require that non-human animal research occur to show the safety and efficacy of new treatments before any human research will be allowed to be conducted.  Not only do we humans benefit from this research and testing, but hundreds of drugs and treatments developed for human use are now routinely used in veterinary clinics as well, helping animals live longer, healthier lives.

It is important to stress that 95% of all animals necessary for biomedical research in the United States are rodents – rats and mice especially bred for laboratory use – and that animals are only one part of the larger process of biomedical research.

Our researchers are strong supporters of animal welfare and view their work with animals in biomedical research as a privilege.

Stanford researchers are obligated to ensure the well-being of all animals in their care..

Stanford researchers are obligated to ensure the well-being of animals in their care, in strict adherence to the highest standards, and in accordance with federal and state laws, regulatory guidelines, and humane principles. They are also obligated to continuously update their animal-care practices based on the newest information and findings in the fields of laboratory animal care and husbandry.  

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• J Prev Med Hyg
• v.63(2 Suppl 3); 2022 Jun

Ethical considerations regarding animal experimentation

Aysha karim kiani.

1 Allama Iqbal Open University, Islamabad, Pakistan

2 MAGI EUREGIO, Bolzano, Italy

DEREK PHEBY

3 Society and Health, Buckinghamshire New University, High Wycombe, UK

GARY HENEHAN

4 School of Food Science and Environmental Health, Technological University of Dublin, Dublin, Ireland

RICHARD BROWN

5 Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada

PAUL SIEVING

6 Department of Ophthalmology, Center for Ocular Regenerative Therapy, School of Medicine, University of California at Davis, Sacramento, CA, USA

PETER SYKORA

7 Department of Philosophy and Applied Philosophy, University of St. Cyril and Methodius, Trnava, Slovakia

ROBERT MARKS

8 Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel

BENEDETTO FALSINI

9 Institute of Ophthalmology, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome, Italy

NATALE CAPODICASA

10 MAGI BALKANS, Tirana, Albania

STANISLAV MIERTUS

11 Department of Biotechnology, University of SS. Cyril and Methodius, Trnava, Slovakia

12 International Centre for Applied Research and Sustainable Technology, Bratislava, Slovakia

LORENZO LORUSSO

13 UOC Neurology and Stroke Unit, ASST Lecco, Merate, Italy

DANIELE DONDOSSOLA

14 Center for Preclincal Research and General and Liver Transplant Surgery Unit, Fondazione IRCCS Ca‘ Granda Ospedale Maggiore Policlinico, Milan, Italy

15 Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy

GIANLUCA MARTINO TARTAGLIA

16 Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy

17 UOC Maxillo-Facial Surgery and Dentistry, Fondazione IRCCS Ca Granda, Ospedale Maggiore Policlinico, Milan, Italy

MAHMUT CERKEZ ERGOREN

18 Department of Medical Genetics, Faculty of Medicine, Near East University, Nicosia, Cyprus

MUNIS DUNDAR

19 Department of Medical Genetics, Erciyes University Medical Faculty, Kayseri, Turkey

SANDRO MICHELINI

20 Vascular Diagnostics and Rehabilitation Service, Marino Hospital, ASL Roma 6, Marino, Italy

DANIELE MALACARNE

21 MAGI’S LAB, Rovereto (TN), Italy

GABRIELE BONETTI

Astrit dautaj, kevin donato, maria chiara medori, tommaso beccari.

22 Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy

MICHELE SAMAJA

23 MAGI GROUP, San Felice del Benaco (BS), Italy

STEPHEN THADDEUS CONNELLY

24 San Francisco Veterans Affairs Health Care System, University of California, San Francisco, CA, USA

DONALD MARTIN

25 Univ. Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, SyNaBi, Grenoble, France

ASSUNTA MORRESI

26 Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy

ARIOLA BACU

27 Department of Biotechnology, University of Tirana, Tirana, Albania

KAREN L. HERBST

28 Total Lipedema Care, Beverly Hills California and Tucson Arizona, USA

MYKHAYLO KAPUSTIN

29 Federation of the Jewish Communities of Slovakia

LIBORIO STUPPIA

30 Department of Psychological, Health and Territorial Sciences, School of Medicine and Health Sciences, University "G. d'Annunzio", Chieti, Italy

LUDOVICA LUMER

31 Department of Anatomy and Developmental Biology, University College London, London, UK

GIAMPIETRO FARRONATO

Matteo bertelli.

32 MAGISNAT, Peachtree Corners (GA), USA

Animal experimentation is widely used around the world for the identification of the root causes of various diseases in humans and animals and for exploring treatment options. Among the several animal species, rats, mice and purpose-bred birds comprise almost 90% of the animals that are used for research purpose. However, growing awareness of the sentience of animals and their experience of pain and suffering has led to strong opposition to animal research among many scientists and the general public. In addition, the usefulness of extrapolating animal data to humans has been questioned. This has led to Ethical Committees’ adoption of the ‘four Rs’ principles (Reduction, Refinement, Replacement and Responsibility) as a guide when making decisions regarding animal experimentation. Some of the essential considerations for humane animal experimentation are presented in this review along with the requirement for investigator training. Due to the ethical issues surrounding the use of animals in experimentation, their use is declining in those research areas where alternative in vitro or in silico methods are available. However, so far it has not been possible to dispense with experimental animals completely and further research is needed to provide a road map to robust alternatives before their use can be fully discontinued.

How to cite this article: Kiani AK, Pheby D, Henehan G, Brown R, Sieving P, Sykora P, Marks R, Falsini B, Capodicasa N, Miertus S, Lorusso L, Dondossola D, Tartaglia GM, Ergoren MC, Dundar M, Michelini S, Malacarne D, Bonetti G, Dautaj A, Donato K, Medori MC, Beccari T, Samaja M, Connelly ST, Martin D, Morresi A, Bacu A, Herbst KL, Kapustin M, Stuppia L, Lumer L, Farronato G, Bertelli M. Ethical considerations regarding animal experimentation. J Prev Med Hyg 2022;63(suppl.3):E255-E266. https://doi.org/10.15167/2421-4248/jpmh2022.63.2S3.2768

Introduction

Animal model-based research has been performed for a very long time. Ever since the 5 th century B.C., reports of experiments involving animals have been documented, but an increase in the frequency of their utilization has been observed since the 19 th century [ 1 ]. Most institutions for medical research around the world use non-human animals as experimental subjects [ 2 ]. Such animals might be used for research experimentations to gain a better understanding of human diseases or for exploring potential treatment options [ 2 ]. Even those animals that are evolutionarily quite distant from humans, such as Drosophila melanogaster , Zebrafish ( Danio rerio ) and Caenorhabditis elegans , share physiological and genetic similarities with human beings [ 2 ]; therefore animal experimentation can be of great help for the advancement of medical science [ 2 ].

For animal experimentation, the major assumption is that the animal research will be of benefit to humans. There are many reasons that highlight the significance of animal use in biomedical research. One of the major reasons is that animals and humans share the same biological processes. In addition, vertebrates have many anatomical similarities (all vertebrates have lungs, a heart, kidneys, liver and other organs) [ 3 ]. Therefore, these similarities make certain animals more suitable for experiments and for providing basic training to young researchers and students in different fields of biological and biomedical sciences [ 3 ]. Certain animals are susceptible to various health problems that are similar to human diseases such as diabetes, cancer and heart disease [ 4 ]. Furthermore, there are genetically modified animals that are used to obtain pathological phenotypes [ 5 ]. A significant benefit of animal experimentation is that test species can be chosen that have a much shorter life cycle than humans. Therefore, animal models can be studied throughout their life span and for several successive generations, an essential element for the understanding of disease progression along with its interaction with the whole organism throughout its lifetime [ 6 ].

Animal models often play a critical role in helping researchers who are exploring the efficacy and safety of potential medical treatments and drugs. They help to identify any dangerous or undesired side effects, such as birth defects, infertility, toxicity, liver damage or any potential carcinogenic effects [ 7 ]. Currently, U.S. Federal law, for example, requires that non-human animal research is used to demonstrate the efficacy and safety of any new treatment options before proceeding to trials on humans [ 8 ]. Of course, it is not only humans benefit from this research and testing, since many of the drugs and treatments that are developed for humans are routinely used in veterinary clinics, which help animals live longer and healthier lives [ 4 ].

COVID-19 AND THE NEED FOR ANIMAL MODELS

When COVID-19 struck, there was a desperate need for research on the disease, its effects on the brain and body and on the development of new treatments for patients with the disease. Early in the disease it was noticed that those with the disease suffered a loss of smell and taste, as well as neurological and psychiatric symptoms, some of which lasted long after the patients had “survived” the disease [ 9-15 ]. As soon as the pandemic started, there was a search for appropriate animal models in which to study this unknown disease [ 16 , 17 ]. While genetically modified mice and rats are the basic animal models for neurological and immunological research [ 18 , 19 ] the need to understand COVID-19 led to a range of animal models; from fruit flies [ 20 ] and Zebrafish [ 21 ] to large mammals [ 22 , 23 ] and primates [ 24 , 25 ]. And it was just not one animal model that was needed, but many, because different aspects of the disease are best studied in different animal models [ 16 , 25 , 26 ]. There is also a need to study the transmission pathways of the zoonosis: where does it come from, what are the animal hosts and how is it transferred to humans [ 27 ]?

There has been a need for animal models for understanding the pathophysiology of COVID-19 [ 28 ], for studying the mechanisms of transmission of the disease [ 16 ], for studying its neurobiology [ 29 , 30 ] and for developing new vaccines [ 31 ]. The sudden onset of the COVID-19 pandemic has highlighted the fact that animal research is necessary, and that the curtailment of such research has serious consequences for the health of both humans and animals, both wild and domestic [ 32 ] As highlighted by Adhikary et al. [ 22 ] and Genzel et al. [ 33 ] the coronavirus has made clear the necessity for animal research and the danger in surviving future such pandemics if animal research is not fully supported. Genzel et al. [ 33 ], in particular, take issue with the proposal for a European ban on animal testing. Finally, there is a danger in bypassing animal research in developing new vaccines for diseases such as COVID-19 [ 34 ]. The purpose of this paper is to show that, while animal research is necessary for the health of both humans and animals, there is a need to carry out such experimentation in a controlled and humane manner. The use of alternatives to animal research such as cultured human cells and computer modeling may be a useful adjunct to animal studies but will require that such methods are more readily accessible to researchers and are not a replacement for animal experimentation.

Pros and cons of animal experimentation

Arguments against animal experimentation.

A fundamental question surrounding this debate is to ask whether it is appropriate to use animals for medical research. Is our acceptance that animals have a morally lower value or standard of life just a case of speciesism [ 35 ]? Nowadays, most people agree that animals have a moral status and that needlessly hurting or abusing pets or other animals is unacceptable. This represents something of a change from the historical point of view where animals did not have any moral status and the treatment of animals was mostly subservient to maintaining the health and dignity of humans [ 36 ].

Animal rights advocates strongly argue that the moral status of non-human animals is similar to that of humans, and that animals are entitled to equality of treatment. In this view, animals should be treated with the same level of respect as humans, and no one should have the right to force them into any service or to kill them or use them for their own goals. One aspect of this argument claims that moral status depends upon the capacity to suffer or enjoy life [ 37 ].

In terms of suffering and the capacity of enjoying life, many animals are not very different from human beings, as they can feel pain and experience pleasure [ 38 ]. Hence, they should be given the same moral status as humans and deserve equivalent treatment. Supporters of this argument point out that according animals a lower moral status than humans is a type of prejudice known as “speciesism” [ 38 ]. Among humans, it is widely accepted that being a part of a specific race or of a specific gender does not provide the right to ascribe a lower moral status to the outsiders. Many advocates of animal rights deploy the same argument, that being human does not give us sufficient grounds declare animals as being morally less significant [ 36 ].

ARGUMENTS IN FAVOR OF ANIMAL EXPERIMENTATION

Those who support animal experimentation have frequently made the argument that animals cannot be elevated to be seen as morally equal to humans [ 39 ]. Their main argument is that the use of the terms “moral status” or “morality” is debatable. They emphasize that we must not make the error of defining a quality or capacity associated with an animal by using the same adjectives used for humans [ 39 ]. Since, for the most part, animals do not possess humans’ cognitive capabilities and lack full autonomy (animals do not appear to rationally pursue specific goals in life), it is argued that therefore, they cannot be included in the moral community [ 39 ]. It follows from this line of argument that, if animals do not possess the same rights as human beings, their use in research experimentation can be considered appropriate [ 40 ]. The European and the American legislation support this kind of approach as much as their welfare is respected.

Another aspect of this argument is that the benefits to human beings of animal experimentation compensate for the harm caused to animals by these experiments.

In other words, animal harm is morally insignificant compared to the potential benefits to humans. Essentially, supporters of animal experimentation claim that human beings have a higher moral status than animals and that animals lack certain fundamental rights accorded to humans. The potential violations of animal rights during animal research are, in this way, justified by the greater benefits to mankind [ 40 , 41 ]. A way to evaluate when the experiments are morally justified was published in 1986 by Bateson, which developed the Bateson’s Cube [ 42 ]. The Cube has three axes: suffering, certainty of benefit and quality of research. If the research is high-quality, beneficial, and not inflicting suffering, it will be acceptable. At the contrary, painful, low-quality research with lower likelihood of success will not be acceptable [ 42 , 43 ].

Impact of experimentations on animals

Ability to feel pain and distress.

Like humans, animal have certain physical as well as psychological characteristics that make their use for experimentation controversial [ 44 ].

In the last few decades, many studies have increased knowledge of animal awareness and sentience: they indicate that animals have greater potential to experience damage than previously appreciated and that current rights and protections need to be reconsidered [ 45 ]. In recent times, scientists as well as ethicists have broadly acknowledged that animals can also experience distress and pain [ 46 ]. Potential sources of such harm arising from their use in research include disease, basic physiological needs deprivation and invasive procedures [ 46 ]. Moreover, social deprivation and lack of the ability to carry out their natural behaviors are other causes of animal harm [ 46 ]. Several studies have shown that, even in response to very gentle handling and management, animals can show marked alterations in their physiological and hormonal stress markers [ 47 ].

In spite of the fact that suffering and pain are personalized experiences, several multi-disciplinary studies have provided clear evidence of animals experiencing pain and distress. In particular, some animal species have the ability to express pain similarly to human due to common psychological, neuroanatomical and genetic characteristics [ 48 ]. Similarly, animals share a resemblance to humans in their developmental, genetic and environmental risk factors for psychopathology. For instance, in many species, it has been shown that fear operates within a less organized subcortical neural circuit than pain [ 49 , 50 ]. Various types of depression and anxiety disorders like posttraumatic stress disorder have also been reported in mammals [ 51 ].

PSYCHOLOGICAL CAPABILITIES OF ANIMALS

Some researchers have suggested that besides their ability to experience physical and psychological pain and distress, some animals also exhibit empathy, self-awareness and language-like capabilities. They also demonstrate tools-linked cognizance, pleasure-seeking and advanced problem-solving skills [ 52 ]. Moreover, mammals and birds exhibit playful behavior, an indicator of the capacity to experience pleasure. Other taxa such as reptiles, cephalopods and fishes have also been observed to display playful behavior, therefore the current legislation prescribes the use of environmental enrichers [ 53 ]. The presence of self-awareness ability, as assessed by mirror self-recognition, has been reported in magpies, chimpanzees and other apes, and certain cetaceans [ 54 ]. Recently, another study has revealed that crows have the ability to create and use tools that involve episodic-like memory formation and its retrieval. From these findings, it may be suggested that crows as well as related species show evidence of flexible learning strategies, causal reasoning, prospection and imagination that are similar to behavior observed in great apes [ 55 ]. In the context of resolving the ethical dilemmas about animal experimentation, these observations serve to highlight the challenges involved [ 56 , 57 ].

Ethics, principles and legislation in animal experimentation

Ethics in animal experimentation.

Legislation around animal research is based on the idea of the moral acceptability of the proposed experiments under specific conditions [ 58 ]. The significance of research ethics that ensures proper treatment of experimental animals [ 58 ]. To avoid undue suffering of animals, it is important to follow ethical considerations during animal studies [ 1 ]. It is important to provide best human care to these animals from the ethical and scientific point of view [ 1 ]. Poor animal care can lead to experimental outcomes [ 1 ]. Thus, if experimental animals mistreated, the scientific knowledge and conclusions obtained from experiments may be compromised and may be difficult to replicate, a hallmark of scientific research [ 1 ]. At present, most ethical guidelines work on the assumption that animal experimentation is justified because of the significant potential benefits to human beings. These guidelines are often permissive of animal experimentation regardless of the damage to the animal as long as human benefits are achieved [ 59 ].

PRINCIPLE OF THE 4 RS

Although animal experimentation has resulted in many discoveries and helped in the understanding numerous aspects of biological science, its use in various sectors is strictly controlled. In practice, the proposed set of animal experiments is usually considered by a multidisciplinary Ethics Committee before work can commence [ 60 ]. This committee will review the research protocol and make a judgment as to its sustainability. National and international laws govern the utilization of animal experimentation during research and these laws are mostly based on the universal doctrine presented by Russell and Burch (1959) known as principle of the 3 Rs. The 3Rs referred to are Reduction, Refinement and Replacement, and are applied to protocols surrounding the use of animals in research. Some researchers have proposed another “R”, of responsibility for the experimental animal as well as for the social and scientific status of the animal experiments [ 61 ]. Thus, animal ethics committees commonly review research projects with reference to the 4 Rs principles [ 62 ].

The first “R”, Reduction means that the experimental design is examined to ensure that researchers have reduced the number of experimental animals in a research project to the minimum required for reliable data [ 59 ]. Methods used for this purpose include improved experimental design, extensive literature search to avoid duplication of experiments [ 35 ], use of advanced imaging techniques, sharing resources and data, and appropriate statistical data analysis that reduce the number of animals needed for statistically significant results [ 2 , 63 ].

The second “R”, Refinement involves improvements in procedure that minimize the harmful effects of the proposed experiments on the animals involved, such as reducing pain, distress and suffering in a manner that leads to a general improvement in animal welfare. This might include for example improved living conditions for research animals, proper training of people handling animals, application of anesthesia and analgesia when required and the need for euthanasia of the animals at the end of the experiment to curtail their suffering [ 63 ].

The third “R”, Replacement refers to approaches that replace or avoid the use of experimental animals altogether. These approaches involve use of in silico methods/computerized techniques/software and in vitro methods like cell and tissue culture testing, as well as relative replacement methods by use of invertebrates like nematode worms, fruit flies and microorganisms in place of vertebrates and higher animals [ 1 ]. Examples of proper application of these first “3R2 principles are the use of alternative sources of blood, the exploitation of commercially used animals for scientific research, a proper training without use of animals and the use of specimen from previous experiments for further researches [ 64-67 ].

The fourth “R”, Responsibility refers to concerns around promoting animal welfare by improvements in experimental animals’ social life, development of advanced scientific methods for objectively determining sentience, consciousness, experience of pain and intelligence in the animal kingdom, as well as effective involvement in the professionalization of the public discussion on animal ethics [ 68 ].

OTHER ASPECTS OF ANIMAL RESEARCH ETHICS

Other research ethics considerations include having a clear rationale and reasoning for the use of animals in a research project. Researchers must have reasonable expectation of generating useful data from the proposed experiment. Moreover, the research study should be designed in such a way that it should involve the lowest possible sample size of experimental animals while producing statistically significant results [ 35 ].

All individual researchers that handle experimental animals should be properly trained for handling the particular species involved in the research study. The animal’s pain, suffering and discomfort should be minimized [ 69 ]. Animals should be given proper anesthesia when required and surgical procedures should not be repeated on same animal whenever possible [ 69 ]. The procedure of humane handling and care of experimental animals should be explicitly detailed in the research study protocol. Moreover, whenever required, aseptic techniques should be properly followed [ 70 ]. During the research, anesthetization and surgical procedures on experimental animals should only be performed by professionally skilled individuals [ 69 ].

The Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines that are issued by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs) are designed to improve the documentation surrounding research involving experimental animals [ 70 ]. The checklist provided includes the information required in the various sections of the manuscript i.e. study design, ethical statements, experimental procedures, experimental animals and their housing and husbandry, and more [ 70 ].

It is critical to follow the highest ethical standards while performing animal experiments. Indeed, most of the journals refuse to publish any research data that lack proper ethical considerations [ 35 ].

INVESTIGATORS’ ETHICS

Since animals have sensitivity level similar to the human beings in terms of pain, anguish, survival instinct and memory, it is the responsibility of the investigator to closely monitor the animals that are used and identify any sign of distress [ 71 ]. No justification can rationalize the absence of anesthesia or analgesia in animals that undergo invasive surgery during the research [ 72 ]. Investigators are also responsible for giving high-quality care to the experimental animals, including the supply of a nutritious diet, easy water access, prevention of and relief from any pain, disease and injury, and appropriate housing facilities for the animal species [ 73 ]. A research experiment is not permitted if the damage caused to the animal exceeds the value of knowledge gained by that experiment. No scientific advancement based on the destruction and sufferings of another living being could be justified. Besides ensuring the welfare of animals involved, investigators must also follow the applicable legislation [ 74 , 75 ].

To promote the comfort of experimental animals in England, an animal protection society named: ‘The Society for the Preservation of Cruelty to Animals’ (now the Royal Society for the Prevention of Cruelty to Animals) was established (1824) that aims to prevent cruelty to animal [ 76 ].

ANIMAL WELFARE LAWS

Legislation for animal protection during research has long been established. In 1876 the British Parliament sanctioned the ‘Cruelty to Animals Act’ for animal protection. Russell and Burch (1959) presented the ‘3 Rs’ principles: Replacement, Reduction and Refinement, for use of animals during research [ 61 ]. Almost seven years later, the U.S.A also adopted regulations for the protection of experimental animals by enacting the Laboratory Animal Welfare Act of 1966 [ 60 ]. In Brazil, the Arouca Law (Law No. 11,794/08) regulates the animal use in scientific research experiments [ 76 ].

These laws define the breeding conditions, and regulate the use of animals for scientific research and teaching purposes. Such legal provisions control the use of anesthesia, analgesia or sedation in experiments that could cause distress or pain to experimental animals [ 59 , 76 ]. These laws also stress the need for euthanasia when an experiment is finished, or even during the experiment if there is any intense suffering for the experimental animal [ 76 ].

Several national and international organizations have been established to develop alternative techniques so that animal experimentation can be avoided, such as the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) ( www.caat.jhsph.edu ), the European Centre for the Validation of Alternative Methods (ECVAM) [ 77 ], the Universities Federation for Animal Welfare (UFAW) ( www.ufaw.org.uk ), The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) [ 78 ], and The Center for Alternatives to Animal Testing (CAAT) ( www.caat.jhsph.edu ). The Brazilian ‘Arouca Law’ also constitutes a milestone, as it has created the ‘National Council for the Control of Animal Experimentation’ (CONCEA) that deals with the legal and ethical issues related to the use of experimental animals during scientific research [ 76 ].

Although national as well as international laws and guidelines have provided basic protections for experimental animals, the current regulations have some significant discrepancies. In the U.S., the Animal Welfare Act excludes rats, mice and purpose-bred birds, even though these species comprise almost 90% of the animals that are used for research purpose [ 79 ]. On the other hand, certain cats and dogs are getting special attention along with extra protection. While the U.S. Animal Welfare Act ignores birds, mice and rats, the U.S. guidelines that control research performed using federal funding ensure protections for all vertebrates [ 79 , 80 ].

Living conditions of animals

Choice of the animal model.

Based on all the above laws and regulations and in line with the deliberations of ethical committees, every researcher must follow certain rules when dealing with animal models.

Before starting any experimental work, thorough research should be carried out during the study design phase so that the unnecessary use of experimental animals is avoided. Nevertheless, certain research studies may have compelling reasons for the use of animal models, such as the investigation of human diseases and toxicity tests. Moreover, animals are also widely used in the training of health professionals as well as in training doctors in surgical skills [ 1 , 81 ].

Researcher should be well aware of the specific traits of the animal species they intend to use in the experiment, such as its developmental stages, physiology, nutritional needs, reproductive characteristics and specific behaviors. Animal models should be selected on the basis of the study design and the biological relevance of the animal [ 1 ].

Typically, in early research, non-mammalian models are used to get rapid insights into research problems such as the identification of gene function or the recognition of novel therapeutic options. Thus, in biomedical and biological research, among the most commonly used model organisms are the Zebrafish, the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans . The main advantage of these non-mammalian animal models is their prolific reproducibility along with their much shorter generation time. They can be easily grown in any laboratory setting, are less expensive than the murine animal models and are somewhat more powerful than the tissue and cell culture approaches [ 82 ].

Caenorhabditis elegans is a small-sized nematode with a short life cycle and that exists in large populations and is relatively inexpensive to cultivate. Scientists have gathered extensive knowledge of the genomics and genetics of Caenorhabditis elegans ; but Caenorhabditis elegans models, while very useful in some respects, are unable to represent all signaling pathways found in humans. Furthermore, due to its short life cycle, scientists are unable to investigate long term effects of test compounds or to analyze primary versus secondary effects [ 6 ].

Similarly, the fruit fly Drosophila melanogaster has played a key role in numerous biomedical discoveries. It is small in size, has a short life cycle and large population size, is relatively inexpensive to breed, and extensive genomics and genetics information is available [ 6 ]. However, its respiratory, cardiovascular and nervous systems differ considerably from human beings. In addition, its immune system is less developed when compared to vertebrates, which is why effectiveness of a drug in Drosophila melanogaster may not be easily extrapolated to humans [ 83 ].

The Zebrafish ( Danio rerio ) is a small freshwater teleost, with transparent embryos, providing easy access for the observation of organogenesis and its manipulation. Therefore, Zebrafish embryos are considered good animal models for different human diseases like tuberculosis and fetal alcohol syndrome and are useful as neurodevelopmental research models. However, Zebrafish has very few mutant strains available, and its genome has numerous duplicate genes making it impossible to create knockout strains, since disrupting one copy of the gene will not disrupt the second copy of that gene. This feature limits the use of Zebrafish as animal models to study human diseases. Additionally they are rather expensive, have long life cycle, and genomics and genetics studies are still in progress [ 82 , 84 ].

Thus, experimentation on these three animals might not be equivalent to experimentation on mammals. Mammalian animal model are most similar to human beings, so targeted gene replacement is possible. Traditionally, mammals like monkey and mice have been the preferred animal models for biomedical research because of their evolutionary closeness to humans. Rodents, particularly mice and rats, are the most frequently used animal models for scientific research. Rats are the most suitable animal model for the study of obesity, shock, peritonitis, sepsis, cancer, intestinal operations, spleen, gastric ulcers, mononuclear phagocytic system, organ transplantations and wound healing. Mice are more suitable for studying burns, megacolon, shock, cancer, obesity, and sepsis as mentioned previously [ 85 ].

Similarly, pigs are mostly used for stomach, liver and transplantation studies, while rabbits are suitable for the study of immunology, inflammation, vascular biology, shock, colitis and transplantations. Thus, the choice of experimental animal mainly depends upon the field of scientific research under consideration [ 1 ].

HOUSING AND ENVIRONMENTAL ENRICHMENT

Researchers should be aware of the environment and conditions in which laboratory animals are kept during research, and they also need to be familiar with the metabolism of the animals kept in vivarium, since their metabolism can easily be altered by different factors such as pain, stress, confinement, lack of sunlight, etc. Housing conditions alter animal behavior, and this can in turn affect experimental results. By contrast, handling procedures that feature environmental enrichment and enhancement help to decrease stress and positively affect the welfare of the animals and the reliability of research data [ 74 , 75 ].

In animals, distress- and agony-causing factors should be controlled or eliminated to overcome any interference with data collection as well as with interpretation of the results, since impaired animal welfare leads to more animal usage during experiment, decreased reliability and increased discrepancies in results along with the unnecessary consumption of animal lives [ 86 ].

To reduce the variation or discrepancies in experimental data caused by various environmental factors, experimental animals must be kept in an appropriate and safe place. In addition, it is necessary to keep all variables like humidity, airflow and temperature at levels suitable for those species, as any abrupt variation in these factors could cause stress, reduced resistance and increased susceptibility to infections [ 74 ].

The space allotted to experimental animals should permit them free movement, proper sleep and where feasible allow for interaction with other animals of the same species. Mice and rats are quite sociable animals and must, therefore, be housed in groups for the expression of their normal behavior. Usually, laboratory cages are not appropriate for the behavioral needs of the animals. Therefore, environmental enrichment is an important feature for the expression of their natural behavior that will subsequently affect their defense mechanisms and physiology [ 87 ].

The features of environmental enrichment must satisfy the animals’ sense of curiosity, offer them fun activities, and also permit them to fulfill their behavioral and physiological needs. These needs include exploring, hiding, building nests and gnawing. For this purpose, different things can be used in their environment, such as PVC tubes, cardboard, igloos, paper towel, cotton, disposable masks and paper strips [ 87 ].

The environment used for housing of animals must be continuously controlled by appropriate disinfection, hygiene protocols, sterilization and sanitation processes. These steps lead to a reduction in the occurrence of various infectious agents that often found in vivarium, such as Sendai virus, cestoda and Mycoplasma pulmonis [ 88 ].

Euthanasia is a term derived from Greek, and it means a death without any suffering. According to the Brazilian Arouca Law (Article 14, Chapter IV, Paragraphs 1 and 2), an animal should undergo euthanasia, in strict compliance with the requirements of each species, when the experiment ends or during any phase of the experiment, wherever this procedure is recommended and/or whenever serious suffering occurs. If the animal does not undergo euthanasia after the intervention it may leave the vivarium and be assigned to suitable people or to the animal protection bodies, duly legalized [ 1 ].

Euthanasia procedures must result in instant loss of consciousness which leads to respiratory or cardiac arrest as well as to complete brain function impairment. Another important aspect of this procedure is calm handling of the animal while taking it out of its enclosure, to reduce its distress, suffering, anxiety and fear. In every research project, the study design should include the details of the appropriate endpoints of these experimental animals, and also the methods that will be adopted. It is important to determine the appropriate method of euthanasia for the animal being used. Another important point is that, after completing the euthanasia procedure, the animal’s death should be absolutely confirmed before discarding their bodies [ 87 , 89 ].

Relevance of animal experimentations and possible alternatives

Relevance of animal experiments and their adverse effects on human health.

One important concern is whether human diseases, when inflicted on experimental animals, adequately mimic the progressions of the disease and the treatment responses observed in humans. Several research articles have made comparisons between human and animal data, and indicated that the results of animals’ research could not always be reliably replicated in clinical research among humans. The latest systematic reviews about the treatment of different clinical conditions including neurology, vascular diseases and others, have established that the results of animal studies cannot properly predict human outcomes [ 59 , 90 ].

At present, the reliability of animal experiments for extrapolation to human health is questionable. Harmful effects may occur in humans because of misleading results from research conducted on animals. For instance, during the late fifties, a sedative drug, thalidomide, was prescribed for pregnant women, but some of the women using that drug gave birth to babies lacking limbs or with foreshortened limbs, a condition called phocomelia. When thalidomide had been tested on almost all animal models such as rats, mice, rabbits, dogs, cats, hamsters, armadillos, ferrets, swine, guinea pig, etc., this teratogenic effect was observed only occasionally [ 91 ]. Similarly, in 2006, the compound TGN 1412 was designed as an immunomodulatory drug, but when it was injected into six human volunteer, serious adverse reactions were observed resulting from a deadly cytokine storm that in turn led to disastrous systemic organ failure. TGN 1412 had been tested successfully in rats, mice, rabbits, and non-human primates [ 92 ]. Moreover, Bailey (2008) reported 90 HIV vaccines that had successful trial results in animals but which failed in human beings [ 93 ]. Moreover, in Parkinson disease, many therapeutic options that have shown promising results in rats and non-human primate models have proved harmful in humans. Hence, to analyze the relevance of animal research to human health, the efficacy of animal experimentation should be examined systematically [ 94 , 95 ]. At the same time, the development of hyperoxaluria and renal failure (up to dialysis) after ileal-jejunal bypass was unexpected because this procedure was not preliminarily evaluated on an animal model [ 96 ].

Several factors play a role in the extrapolation of animal-derived data to humans, such as environmental conditions and physiological parameters related to stress, age of the experimental animals, etc. These factors could switch on or off genes in the animal models that are specific to species and/or strains. All these observations challenge the reliability and suitability of animal experimentation as well as its objectives with respect to human health [ 76 , 92 ].

ALTERNATIVE TO ANIMAL EXPERIMENTATION/DEVELOPMENT OF NEW PRODUCTS AND TECHNIQUES TO AVOID ANIMAL SACRIFICE IN RESEARCH

Certainly, in vivo animal experimentation has significantly contributed to the development of biological and biomedical research. However it has the limitations of strict ethical issues and high production cost. Some scientists consider animal testing an ineffective and immoral practice and therefore prefer alternative techniques to be used instead of animal experimentation. These alternative methods involve in vitro experiments and ex vivo models like cell and tissue cultures, use of plants and vegetables, non-invasive human clinical studies, use of corpses for studies, use of microorganisms or other simpler organism like shrimps and water flea larvae, physicochemical techniques, educational software, computer simulations, mathematical models and nanotechnology [ 97 ]. These methods and techniques are cost-effective and could efficiently replace animal models. They could therefore, contribute to animal welfare and to the development of new therapies that can identify the therapeutics and related complications at an early stage [ 1 ].

The National Research Council (UK) suggested a shift from the animal models toward computational models, as well as high-content and high-throughput in vitro methods. Their reports highlighted that these alternative methods could produce predictive data more affordably, accurately and quickly than the traditional in vivo or experimental animal methods [ 98 ].

Increasingly, scientists and the review boards have to assess whether addressing a research question using the applied techniques of advanced genetics, molecular, computational and cell biology, and biochemistry could be used to replace animal experiments [ 59 ]. It must be remembered that each alternative method must be first validated and then registered in dedicated databases.

An additional relevant concern is how precisely animal data can mirror relevant epigenetic changes and human genetic variability. Langley and his colleagues have highlighted some of the examples of existing and some emerging non-animal based research methods in the advanced fields of neurology, orthodontics, infectious diseases, immunology, endocrine, pulmonology, obstetrics, metabolism and cardiology [ 99 ].

IN SILICO SIMULATIONS AND INFORMATICS

Several computer models have been built to study cardiovascular risk and atherosclerotic plaque build-up, to model human metabolism, to evaluate drug toxicity and to address other questions that were previously approached by testing in animals [ 100 ].

Computer simulations can potentially decrease the number of experiments required for a research project, however simulations cannot completely replace laboratory experiments. Unfortunately, not all the principles regulating biological systems are known, and computer simulation provide only an estimation of possible effects due to the limitations of computer models in comparison with complex human tissues. However, simulation and bio-informatics are now considered essential in all fields of science for their efficiency in using the existing knowledge for further experimental designs [ 76 ].

At present, biological macromolecules are regularly simulated at various levels of detail, to predict their response and behavior under certain physical conditions, chemical exposures and stimulations. Computational and bioinformatic simulations have significantly reduced the number of animals sacrificed during drug discovery by short listing potential candidate molecules for a drug. Likewise, computer simulations have decreased the number of animal experiments required in other areas of biological science by efficiently using the existing knowledge. Moreover, the development of high definition 3D computer models for anatomy with enhanced level of detail, it may make it possible to reduce or eliminate the need for animal dissection during teaching [ 101 , 102 ].

3D CELL-CULTURE MODELS AND ORGANS-ON-CHIPS

In the current scenario of rapid advancement in the life sciences, certain tissue models can be built using 3D cell culture technology. Indeed, there are some organs on micro-scale chip models used for mimicking the human body environment. 3D models of multiple organ systems such as heart, liver, skin, muscle, testis, brain, gut, bone marrow, lungs and kidney, in addition to individual organs, have been created in microfluidic channels, re-creating the physiological chemical and physical microenvironments of the body [ 103 ]. These emerging techniques, such as the biomedical/biological microelectromechanical system (Bio-MEMS) or lab-on-a-chip (LOC) and micro total analysis systems (lTAS) will, in the future, be a useful substitute for animal experimentation in commercial laboratories in the biotechnology, environmental safety, chemistry and pharmaceutical industries. For 3D cell culture modeling, cells are grown in 3D spheroids or aggregates with the help of a scaffold or matrix, or sometimes using a scaffold-free method. The 3D cell culture modeling conditions can be altered to add proteins and other factors that are found in a tumor microenvironment, for example, or in particular tissues. These matrices contain extracellular matrix components such as proteins, glycoconjugates and glycosaminoglycans that allow for cell communication, cell to cell contact and the activation of signaling pathways in such a way that the morphological and functional differentiation of these cells can accurately mimic their environment in vivo . This methodology, in time, will bridge the gap between in vivo and in vitro drug screening, decreasing the utilization of animal models during research [ 104 ].

ALTERNATIVES TO MICROBIAL CULTURE MEDIA AND SERUM-FREE ANIMAL CELL CULTURES

There are moves to reduce the use of animal derived products in many areas of biotechnology. Microbial culture media peptones are mostly made by the proteolysis of farmed animal meat. However, nowadays, various suppliers provide peptones extracted from yeast and plants. Although the costs of these plant-extracted peptones are the same as those of animal peptones, plant peptones are more environmentally favorable since less plant material and water are required for them to grow, compared with the food grain and fodder needed for cattle that are slaughtered for animal peptone production [ 105 ].

Human cell culture is often carried out in a medium that contains fetal calf serum, the production of which involves animal (cow) sacrifice or suffering. In fact, living pregnant cows are used and their fetuses removed to harvest the serum from the fetal blood. Fetal calf serum is used because it is a natural medium rich in all the required nutrients and significantly increases the chances of successful cell growth in culture. Scientists are striving to identify the factors and nutrients required for the growth of various types of cells, with a view to eliminating the use of calf serum. At present, most cell lines could be cultured in a chemically-synthesized medium without using animal products. Furthermore, data from chemically-synthesized media experiments may have better reproducibility than those using animal serum media, since the composition of animal serum does change from batch to batch on the basis of animals’ gender, age, health and genetic background [ 76 ].

ALTERNATIVES TO ANIMAL-DERIVED ANTIBODIES

Animal friendly affinity reagents may act as an alternative to antibodies produced, thereby removing the need for animal immunization. Typically, these antibodies are obtained in vitro by yeast, phage or ribosome display. In a recent review, a comparative analysis between animal friendly affinity reagents and animal derived-antibodies showed that the affinity reagents have superior quality, are relatively less time consuming, have more reproducibility and are more reliable and are cost-effective [ 106 , 107 ].

Conclusions

Animal experimentation led to great advancement in biological and biomedical sciences and contributed to the discovery of many drugs and treatment options. However, such experimentation may cause harm, pain and distress to the animals involved. Therefore, to perform animal experimentations, certain ethical rules and laws must be strictly followed and there should be proper justification for using animals in research projects. Furthermore, during animal experimentation the 4 Rs principles of reduction, refinement, replacement and responsibility must be followed by the researchers. Moreover, before beginning a research project, experiments should be thoroughly planned and well-designed, and should avoid unnecessary use of animals. The reliability and reproducibility of animal experiments should also be considered. Whenever possible, alternative methods to animal experimentation should be adopted, such as in vitro experimentation, cadaveric studies, and computer simulations.

While much progress has been made on reducing animal experimentation there is a need for greater awareness of alternatives to animal experiments among scientists and easier access to advanced modeling technologies. Greater research is needed to define a roadmap that will lead to the elimination of all unnecessary animal experimentation and provide a framework for adoption of reliable alternative methodologies in biomedical research.

Acknowledgements

This research was funded by the Provincia Autonoma di Bolzano in the framework of LP 15/2020 (dgp 3174/2021).

Conflicts of interest statement

Authors declare no conflict of interest.

Author's contributions

MB: study conception, editing and critical revision of the manuscript; AKK, DP, GH, RB, Paul S, Peter S, RM, BF, NC, SM, LL, DD, GMT, MCE, MD, SM, Daniele M, GB, AD, KD, MCM, TB, MS, STC, Donald M, AM, AB, KLH, MK, LS, LL, GF: literature search, editing and critical revision of the manuscript. All authors have read and approved the final manuscript.

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VA continues ‘approved’ experiments on dogs, cats and monkeys after Congress orders an end to live-animal tests by 2026

A hospital staff member took this 2019 photo of a cat used in experiments at the Louis Stokes Cleveland VA Medical Center. Tests involved placing electrodes in the cat’s bladder and using a device to stimulate urination. The VA in 2024 is seeking to implant wires and sensors in the legs and backs of cats in a separate experiment to test an implant for translating signals from a prosthesis to the nervous system. (White Coat Waste Project)

WASHINGTON — Researchers from the Department of Veterans Affairs will implant pacemakers in the hearts of 54 dogs that will be euthanized at the end of the tests and surgically embed wires and sensors into the backs and legs of cats in separate experiments that the VA plans to conduct on live animals in 2024, according to agency documents.

Though the Department of Veterans Affairs is under order by Congress to phase out live animal experiments using cats, dogs and primates “with limited exceptions” by 2026, the agency continues to support live-animal research at VA facilities across the U.S., according to the VA.

More than 62,000 cats and dogs are in U.S. labs for live animal experiments run by government agencies, colleges and universities, and private companies, according to the Humane Society of the United States, a nonprofit organization that focuses on the welfare of animals.

The VA has been phasing out live animal testing on dogs, cats and primates since 2018.

Terrence Hayes, the VA press secretary, said the agency is assessing a new congressional directive adopted in March to eliminate the live-animal tests “with limited exceptions” within two years.

“VA is reviewing the recently signed fiscal year 2024 appropriations law to ensure any implementation of the new provisions fully meet congressional intent, including using of funding, program requirements and reporting to our congressional partners,” he said.

A provision requiring the VA to end live animal research is part of the Consolidated Appropriations Act, signed into law March 9. The legislation requires the VA to provide a plan for ending the tests within 90 days of the bill’s enactment.

In 2024, the VA’s list of “approved research” on live animals includes two separate experiments using dogs at the Richmond VA Medical Center in Virginia.

The experiments involve implanting pacemakers in the hearts of dogs to induce extra heartbeats that disrupt the regular heart rhythm, causing a sensation of fluttering in the chest. The purpose is to measure deteriorating heart muscle and heart failure caused by the extra heart beats.

The dogs will undergo open heart surgery to implant a pacemaker device and a radio telemetry system. Catheters also will be positioned on the heart surface, according to the project description.

Fifty-four dogs will be used in the experiment, after which “most will be euthanized,” according to VA documents.

Dogs not euthanized will be granted a four-week recovery at which time the pacemakers will be disabled, and the animals further studied. Those dogs also will be euthanized at the conclusion of the tests.

The White Coat Waste Project, a nonprofit watchdog group, said records obtained by the organization under the Freedom of Information Act show no dogs are currently confined at the Richmond VA Medical Center or being used there for heart experiments.

A separate VA experiment using cats is approved for 2024 for the Louis Stokes VA Medical Center in Cleveland for testing the durability of implanted medical devices to stimulate nerve sensation in patients who have undergone amputations.

“New prosthetic technology for amputees can restore natural sensations,” according to the project proposal published by the National Institutes of Health.

Funding through September for the experiments is about $270,000, according to information the VA published on its website.

The experiments involve surgically embedding wires and sensors into the legs and backs of cats, according to documents obtained by the White Coat Waste Project.

The procedures risk paralysis and death in the cats, which is counter to directives by Congress for restricting these types of tests, said Justin Goodman, senior vice president of White Coat Waste Project.

The experiment is to test a miniaturized implant that translates electrical signals from a prosthesis to the nervous system, which could allow veterans who lost a limb to achieve a better sense of balance and motion in digits and joints, Hayes said.

He described the experiments as safe and said the cats will be placed into adoptive homes at the conclusion of the research in six months.

The VA also has approval in 2024 to continue experiments on dozens of rhesus macaque monkeys for measuring treatment outcomes for spinal cord injuries.

The experiment at the VA San Diego Health Care System involves damaging a monkey’s spinal cord in surgical procedures.

The monkey then undergoes “multiple major survival surgeries” along with stem cell therapy to address injuries and observe recoveries.

“Each of these surgeries will add to the body of knowledge we can gain about recovery from spinal cord injury,” according to the project description on the VA website.

“This research is to explore the possibility that neural stem cells can be used to help bridge the damaged tissue and restore communication across the site of the injury,” according to the project description.

The experiment identifies the use of restraint chairs for behavioral testing to force monkeys recovering from spinal cord injuries to use the hand with limited use to perform tasks. The monkeys also are expected to walk on treadmills and retrieve food to improve function, according to the project description.

The experiments using the monkeys are being conducted in conjunction with other agencies including University of California-Davis, which has one of the biggest primate laboratories in the country, Goodman said.

Animals are purchased from breeders licensed to sell dogs, cats, primates and other animals to laboratories for use in live-animal experiments.

Goodman said his organization objects to the VA using taxpayer dollars to purchase animals and submit them to painful experiments. He said animals often are euthanized and dissected at the end of the research, as part of the study.

previous coverage

• VA ordered to end experiments on dogs, cats and primates by 2026

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Animal Testing Facts and Alternatives

Right now, millions of  mice ,  rats ,  rabbits ,  primates ,  cats ,  dogs , and other animals are locked inside barren cages in laboratories across the country. They languish in pain, suffer from extreme frustration, ache with loneliness, and long to be free.

Instead, all they can do is sit and wait in fear of the next terrifying and painful procedure that will be performed on them. The complete lack of environmental enrichment and the stress of their living situation cause some animals to develop neurotic types of behavior such as incessantly spinning in circles, rocking back and forth, pulling out their own fur, and even biting themselves. After enduring a life of pain, loneliness, and terror, almost all of them will be killed.

There are many non-animal test methods that can be used in place of animal testing. Not only are these non-animal tests more humane, they also have the potential to be cheaper, faster, and more relevant to humans.

While some of the experimentation conducted on animals today is required by law, most of it isn’t. In fact, a number of countries have implemented bans on the testing of certain types of consumer goods on animals, such as the cosmetics-testing bans in the European Union, India, Israel, New Zealand, Norway, and elsewhere.

Millions of Animals Suffer and Die in Testing, Training, and Other Experiments

More than 100 million animals suffer and die in the U.S. every year in cruel chemical, drug, food, and cosmetics tests as well as in  medical training exercises   and curiosity-driven  medical experiments at universities . Animals also suffer and die in  classroom biology experiments and dissection , even though modern non-animal tests have repeatedly been shown to have more educational value, save teachers time, and save schools money. Exact numbers aren’t available because mice, rats, birds, and cold-blooded animals—who make up more than 99 percent of animals used in experiments—are not covered by even the minimal protections of the Animal Welfare Act and therefore go uncounted.

Examples of animal tests include forcing mice and rats to inhale toxic fumes, force-feeding dogs pesticides, and dripping corrosive chemicals into rabbits’ sensitive eyes. Even if a product harms animals, it can still be marketed to consumers. Conversely, just because a product was shown to be safe in animals does not guarantee that it will be safe to use in humans.

Taxpayer and Health Charities’ Dollars Fund Experiments on Animals

Animals are also used in toxicity tests conducted as part of massive  regulatory testing  programs that are often funded by U.S. taxpayers’ money. The  Environmental Protection Agency , the  Food and Drug Administration , the  National Toxicology Program , and the U.S. Department of Agriculture are just a few of the government agencies that subject animals to crude, painful tests.

The federal government and many health charities waste precious dollars from taxpayers and well-meaning donors on animal experiments at universities and private laboratories, instead of supporting promising clinical, in vitro , epidemiological, and other non-animal studies that could actually benefit humans.

A Century of Suffering

Experimenters have tortured animals in laboratories throughout history. “ Without Consent ,” PETA’s interactive timeline, features almost 200 stories of twisted experiments, including ones in which dogs were forced to inhale cigarette smoke for months, mice were cut up while still conscious, and cats were deafened, paralyzed, and drowned. Visit “ Without Consent ” to learn about more harrowing animal experiments throughout history and how you can help create a better future for living, feeling beings.

What You Can Do

Each of us can help prevent animal suffering and deaths by buying  cruelty-free products , donating only to charities that don’t experiment on animals, requesting alternatives to animal dissection, demanding the immediate implementation of humane, effective non-animal tests by government agencies and corporations, and calling on our alma maters to stop experimenting on animals.

With the  help  of our members and supporters, PETA campaigns globally to expose and end the use of animals in experiments. Some of our efforts include the following:

• Conducting groundbreaking eyewitness investigations and colorful advocacy campaigns to educate the public
• Pushing government agencies to stop  funding  and  conducting  experiments on animals
• Encouraging  pharmaceutical, chemical , and  consumer product companies  to replace tests on animals with more effective non-animal methods
• Helping  students  and  teachers  end dissection in the classroom
• Funding  humane non-animal research
• Publishing scientific papers on the superiority of non-animal test methods
• Urging  health charities  not to invest in dead-end tests on animals

This multifaceted approach yields scores of  victories  for animals imprisoned in laboratories every year.

Please immediately tell the U.S. Fish & Wildlife Service not to resume monkey imports from Cambodia.

Removing the protection of rhesus macaque monkeys will expose them to capture, abuse, and exploitation.

A just-released report reveals a laundry list of violations in a tax-funded laboratory at Emory University, where, among other horrors, experimenters caused a baby monkey to suffer.

Please urge SkyTaxi to stop flying these animals to their deaths.

Please urge the FDA not to ask for animal tests and to instead collaborate on the development of a non-animal testing approach that protects human health without harming animals.

PETA shut down one miserable lab in Colombia and got the authorities to rescue all the animals. Now, we’ve uncovered another. We need your help to stop it from killing any more monkeys.

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“Almost all of us grew up eating meat, wearing leather, and going to circuses and zoos. We never considered the impact of these actions on the animals involved. For whatever reason, you are now asking the question: Why should animals have rights? ”

— Ingrid E. Newkirk, PETA President and co-author of Animalkind

Text CRAZY to 73822 to take action for chimpanzees suffering in human homes & roadside zoos! Then watch Chimp Crazy, HBO’s new docuseries to learn more.

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News | Science

Testing on live animals fell by 3% last year, data suggests

The number of tests carried out on live animals last year fell by 3%, new data shows.

Across Great Britain 2.68 million scientific procedures were carried out on animals in 2023 – down from 2.76 million in 2022 – representing the lowest number since 2001.

Data from the Home Office shows that experimental procedures (1.47 million) fell by 3%, and procedures for creation and breeding also decreased by 3% on the previous year.

Experimental tests made up some 55% of all procedures in 2023, the figures for England , Scotland and Wales show.

Mice, fish, birds or rats were used in the vast majority (95%) of procedures, and these animals have been the most used for more than a decade.

According to the data, procedures on specially protected species – cats, dogs, horses and non-human primates – accounted for use in 1.2% of experimental procedures in 2023.

Twenty-one dogs were used for the creation and breeding of genetically altered (GA) animals.

Experimental procedures were conducted for the purposes of basic research and the development of treatments, safety testing of pharmaceuticals and other substances.

Some 52% of experimental procedures were for basic research, and the top three research areas were the nervous system, the immune system and cancer.

Animal research remains a small but vital part of biomedical research dedicated to elucidating the mechanisms of infectious or non-communicable diseases, such as multiple sclerosis, stroke or dementia, or the testing of potential new treatments

Dr Mark Down, Royal Society of Biology

Dr Mark Down, chief executive of the Royal Society of Biology, said: “The advancement of biological science and the development of biomedical treatments, for humans and animals alike, will require the regulated use of animals in science for the foreseeable future.

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“Animal research remains a small but vital part of biomedical research dedicated to elucidating the mechanisms of infectious or non-communicable diseases, such as multiple sclerosis, stroke or dementia, or the testing of potential new treatments.”

Some animals may be used more than once in certain circumstances so the number of procedures carried out in a year does not equal the number of animals used.

Looking at the countries individually, the number of procedures in England and Scotland fell by 3% and 2% respectively in the last year.

The number of procedures that took place in Wales decreased by 19% compared with 2022.

Understanding Animal Research (UAR), an organisation which promotes open communications on the issue, said animal testing is a small but important part of the research into new medicines, vaccines and treatments for humans and animals.

According to UAR, 10 organisations accounted for more than half (54%) of all animal research in Britain last year.

They were the University of Cambridge, University of Oxford, the Francis Crick Institute, UCL, University of Edinburgh, the Medical Research Council, University of Manchester, King’s College London, University of Glasgow, and Imperial College London.

Cutting-edge non-animal methods, such as organs-on-chips, are widely available, and clinging to testing on animals is not only barbaric but also irresponsible

Dr Julia Baines, People for the Ethical Treatment of Animals

The 10 listed institutes were responsible for 1,435,009 procedures, and of these, more than 99% were carried out on mice, fish and rats and 82% were classified as causing pain equivalent to, or less than, an injection.

Wendy Jarrett, chief executive of UAR,  which developed the Concordat on Openness, said: “Animal research remains a small but vital part of the quest for new medicines, vaccines and treatments for humans and animals.

“Alternative methods are gradually being phased in but, until we have sufficient reliable alternatives available, it is important that organisations that use animals in research maintain the public’s trust in them.

“By providing this level of information about the numbers of animals used, and the experience of those animals, as well as details of the medical breakthroughs that derive from this research, these concordat signatories are helping the public to make up their own minds about how they feel about the use of animals in scientific research in Great Britain.”

Dr Julia Baines, senior science policy manager at People for the Ethical Treatment of Animals (Peta), said: “There’s simply no excuse for subjecting rats, dogs, mice, and other animals – who feel fear, pain, and loneliness just like we do – to experiments in which chemicals are applied to their exposed brains, forcing fevers and triggering seizures.

“Cutting-edge non-animal methods, such as organs-on-chips, are widely available, and clinging to testing on animals is not only barbaric but also irresponsible.

“Despite decades of pretending to the public that it diligently seeks to reduce, refine, and replace the use of animals in laboratories, the former government didn’t go nearly far enough.”

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