Using animals in experiments | The Humane Society of the United ...

How many animals are used in experiments each year?
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.
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 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.
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 into sanctuaries.
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 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 potentially toxic drugs 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.
What kinds of institutions use animals in experiments?
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.
Where do laboratories get the animals they use 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.
What is life like for animals in laboratories?
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.
What happens to the animals once an experiment is over?
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.
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 2022, 15 states have such laws.
Aren’t there laws to protect animals used in experiments?
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.
Why are animals still used in experiments?
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.
What are the alternatives to experiments on animals?
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 animal experiments 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 funding to develop new methods. A concerted effort to shift funding and technological development toward more non-animal alternatives will lead us to a future where animal experiments will ultimately become 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.
What are you doing to end experiments on animals?
We advocate for replacing animals with non-animal alternative methods when they are available and funding 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 December 2022, 10 states (California, Hawaii, Illinois, Louisiana, Maine, Maryland, Nevada, New Jersey, New York and Virginia) have passed laws banning the sale of animal-tested cosmetics.
Internationally, as of December 2022, 42 countries have passed laws to limit or ban cosmetics animal testing, including every country in the European Union, Australia, Colombia, Ecuador, Guatemala, Iceland, India, Israel, Mexico, New Zealand, Norway, South Korea, Switzerland, Taiwan, Turkey, the United Kingdom and several states in Brazil.
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.
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.
We are calling on federal agencies to develop a plan and create a timetable for phasing out and ending all experiments on dogs. We also want all the federal funding mechanisms to commit to supporting the development and use of non-animal methods. For example:
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.
We are pushing states to pass laws that protect dogs in laboratories. We support bills to:
prohibit or limit the use of dogs in experiments not required by federal law.
What can I do to help animals in laboratories?
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:
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, 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 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.
Also of interest:
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