Animal testing is cruel and inhumane. According to Humane Society International, animals used in experiments are commonly subjected to force feeding, forced inhalation, food and water deprivation, prolonged periods of physical restraint, the infliction of burns and other wounds to study the healing process, the infliction of pain to study its effects and remedies, and "killing by carbon dioxide asphyxiation, neck-breaking, decapitation, or other means." [47] The Draize eye test, used by cosmetics companies to evaluate irritation caused by shampoos and other products, involves rabbits being incapacitated in stocks with their eyelids held open by clips, sometimes for multiple days, so they cannot blink away the products being tested. [48][49] The commonly used LD50 (lethal dose 50) test involves finding out which dose of a chemical will kill 50% of the animals being used in the experiment. [65][102] The US Department of Agriculture (USDA) reported in 2016 that 71,370 animals suffered pain during experiments while being given no anesthesia for relief, including 1,272 nonhuman primates, 5,771 rabbits, 24,566 guinea pigs, and 33,280 hamsters. [

Alternative testing methods now exist that can replace the need for animals. In vitro (in glass) testing, such as studying cell cultures in a petri dish, can produce more relevant results than animal testing because human cells can be used. [15] Microdosing, the administering of doses too small to cause adverse reactions, can be used in human volunteers, whose blood is then analyzed. Artificial human skin, such as the commercially available products EpiDerm and ThinCert, is made from sheets of human skin cells grown in test tubes or plastic wells and can produce more useful results than testing chemicals on animal skin. [15][50][51] Microfluidic chips ("organs on a chip"), which are lined with human cells and recreate the functions of human organs, are in advanced stages of development. Computer models, such as virtual reconstructions of human molecular structures, can predict the toxicity of substances without invasive experiments on animals.

Animals are very different from human beings and therefore make poor test subjects. The anatomic, metabolic, and cellular differences between animals and people make animals poor models for human beings. [52] Paul Furlong, Professor of Clinical Neuroimaging at Aston University (UK), states that "it's very hard to create an animal model that even equates closely to what we're trying to achieve in the human." [53] Thomas Hartung, Professor of evidence-based toxicology at Johns Hopkins University, argues for alternatives to animal testing because "we are not 70 kg rats."

Drugs that pass animal tests are not necessarily safe. The 1950s sleeping pill thalidomide, which caused 10,000 babies to be born with severe deformities, was tested on animals prior to its commercial release. [5] Later tests on pregnant mice, rats, guinea pigs, cats, and hamsters did not result in birth defects unless the drug was administered at extremely high doses. [109][110] Animal tests on the arthritis drug Vioxx showed that it had a protective effect on the hearts of mice, yet the drug went on to cause more than 27,000 heart attacks and sudden cardiac deaths before being pulled from the market.

Animal tests may mislead researchers into ignoring potential cures and treatments. Some chemicals that are ineffective on, or harmful to, animals prove valuable when used by humans. Aspirin, for example, is dangerous for some animal species. [105] Intravenous vitamin C has shown to be effective in treating sepsis in humans, but makes no difference to mice. [127] Fk-506 (tacrolimus), used to lower the risk of organ transplant rejection, was "almost shelved" because of animal test results, according to neurologist Aysha Akhtar, MD, MPH. [105] A report on Slate.com stated that a "source of human suffering may be the dozens of promising drugs that get shelved when they cause problems in animals that may not be relevant for humans."

95% of animals used in experiments are not protected by the Animal Welfare Act. The AWA does not cover rats, mice, fish and birds, which comprise around 95% of the animals used in research. The AWA covered 820,812 animals used for testing in fiscal year 2016, which leaves around 25 million other animals that are not covered. These animals are especially vulnerable to mistreatment and abuse without the protection of the AWA.

Animal tests do not reliably predict results in human beings. 94% of drugs that pass animal tests fail in human clinical trials. [57] According to neurologist Aysha Akhtar, MD, MPH, over 100 stroke drugs that were effective when tested on animals have failed in humans, and over 85 HIV vaccines failed in humans after working well in non-human primates. [58] A study published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) found that nearly 150 clinical trials (human tests) of treatments to reduce inflammation in critically ill patients have been undertaken, and all of them failed, despite being successful in animal tests. [59][58] A study in Archives of Toxicology stated that "The low predictivity of animal experiments in research areas allowing direct comparisons of mouse versus human data puts strong doubt on the usefulness of animal data as key technology to predict human safety."

Animal tests are more expensive than alternative methods and are a waste of government research dollars. Humane Society International compared a variety of animal tests with their in vitro counterparts and found animal tests were more expensive in every scenario studied. [61] [62] Biotechnology company Empiriko invented synthetic livers which can predict the liver's metabolic reactions to drugs in a process that is quicker, cheaper, and more accurate than animal testing; in one trial it provided a level of specificity which previously would have required testing on 1,000 rats and 100 dogs. [124] According to Senator Jeff Flake's "Wastebook" of government funding, over $7.3 million of taxpayers' money was wasted on studies involving animals in 2016. [125] People for the Ethical Treatment of Animals (PETA) found $56.4 million of government funds spent on animal experiments that, despite running over many years, failed to provide any useful results.

Most experiments involving animals are flawed, wasting the lives of the animal subjects. A peer-reviewed study found serious flaws in the majority of publicly funded US and UK animal studies using rodents and primates. 87% of the studies failed to randomize the selection of animals (a technique used to reduce "selection bias") and 86% did not use "blinding" (another technique to reduce researcher bias). Also, "only 59% of the studies stated the hypothesis or objective of the study and the number and characteristics of the animals used." [64] A 2017 study found further flaws in animal studies including "incorrect data interpretation, unforeseen technical issues, incorrectly constituted (or absent) control groups, selective data reporting, inadequate or varying software systems, and blatant fraud." [128] Since the majority of animals used in biomedical research are killed during or after the experiments, and since many suffer during the studies, the lives and wellbeing of animals are routinely sacrificed for poor research.

Animals can suffer like humans do, so it is speciesism to experiment on them while we refrain from experimenting on humans. All suffering is undesirable, whether it be in humans or animals. Discriminating against animals because they do not have the cognitive ability, language, or moral judgment that humans do is no more justifiable than discriminating against human beings with severe mental impairments. [66][67] As English philosopher Jeremy Bentham wrote in the 1700s, "The question is not, Can they reason? nor, Can they talk? but, Can they suffer?"

The Animal Welfare Act has not succeeded in preventing horrific cases of animal abuse in research laboratories. Violations of the Animal Welfare Act at the federally funded New Iberia Research Center (NIRC) in Louisiana included maltreatment of primates who were suffering such severe psychological stress that they engaged in self-mutilation, infant primates awake and alert during painful experiments, and chimpanzees being intimidated and shot with a dart gun. [68] An incident at the University of California at Davis Center for Neuroscience, "three baby mice were found sealed alive in a plastic baggie and left unattended" on a laboratory counter, according to the Sacramento Bee. [69] A US Department of Agriculture (USDA) lawsuit against Shin Nippon Biomedical Laboratories (SNBL) of Everett, WA, alleged willful violation of the AWA, including the death of 38 primates from dehydration, hypoglycemia, suffocation, hyperthermia, and seizures.

Religious traditions tell us to be merciful to animals, so we should not cause them suffering by experimenting on them. In the Bible, Proverbs 12:10 states: "A righteous man regardeth the life of his beast..." [70] The Hindu doctrine of ahimsa teaches the principle of not doing harm to other living beings. [103] The Buddhist doctrine of right livelihood dissuades Buddhists from doing any harm to animals

Medical breakthroughs involving animal research may still have been made without the use of animals. There is no evidence that animal experiments were essential in making major medical advances, and if enough money and resources were devoted to animal-free alternatives, other solutions would be found. [107] [129] [130] Humane Research Australia (HRA) reports that many discoveries made by non-animal methods were later verified by animal experiments, "giving false credit" to animal use. [130] For example, HRA notes, "Ovarian function was demonstrated by physician Dr. Robert.T. Morris in 1895 in surgical procedures on women, yet history credits the discovery to Emil Knauer who reproduced the procedure in rabbits in 1896... [and] Banting and Best are often cited as having discovered insulin through animal experiments in 1922. However... the discovery of insulin dates back to 1788 when an English physician, Thomas Cawley, performed an autopsy on a diabetic.