Arguments against animal testing
Animal experiments are cruel, unreliable, and even dangerous
The harmful use of animals in experiments is not only cruel but also often ineffective. Animals do not get many of the human diseases that people do, such as major types of heart disease, many types of cancer, HIV, Parkinson’s disease, or schizophrenia. Instead, signs of these diseases are artificially induced in animals in laboratories in an attempt to mimic the human disease. Yet, such experiments belittle the complexity of human conditions which are affected by wide-ranging variables such as genetics, socio-economic factors, deeply-rooted psychological issues and different personal experiences.
It is not surprising to find that treatments showing ‘promise’ in animals rarely work in humans. Not only are time, money and animals’ lives being wasted (with a huge amount of suffering), but effective treatments are being mistakenly discarded and harmful treatments are getting through. The support for animal testing is based largely on anecdote and is not backed up, we believe, by the scientific evidence that is out there.
Despite many decades of studying conditions such as cancer, Alzheimer’s disease, Parkinson’s disease, diabetes, stroke and AIDS in animals, we do not yet have reliable and fully effective cures.
The history of cancer research has been the history of curing cancer in the mouse. We have cured mice of cancer for decades and it simply didn’t work in human beings. Dr. Richard Klausner, former director of the US National Cancer Institute
Unreliable animal testing
- 90% of drugs fail in human trials despite promising results in animal tests – whether on safety grounds or because they do not work
- Cancer drugs have the lowest success rate (only 5% are approved after entering clinical trials) followed by psychiatry drugs (6% success rate), heart drugs (7% success rate) and neurology drugs (8% success rate).
- Using dogs, rats, mice and rabbits to test whether or not a drug will be safe for humans provides little statistically useful insight, our recent analysis found. The study also revealed that drug tests on monkeys are just as poor as those using any other species in predicting the effects on humans.
- Out of 93 dangerous drug side effects, only 19% could have been predicted by animal tests, a recent study found
- Using mice and rats to test the safety of drugs in humans is only accurate 43% of the time, a recent study found
- Out of 48 cancer drugs approved by the European Medicines Agency from 2009 to 2013 to treat 68 types of cancer, almost half showed no survival benefits according to a recent study. Even in cases where benefits were seen, the difference was judged to be ‘clinically insignificant’.
Wasteful animal testing
- Despite the use of over 115 million animals in experiments globally each year, only 59 new medicines were approved in 2018 by the leading drug regulator, the U.S. Food and Drug Administration. Many of these are for rare diseases.
- The US drug industry invests $50 billion per year in research, but the approval rate of new drugs is the same as it was 50 years ago.Only 6% of 4,300 international companies involved in drug development have registered a new drug with the U.S. Food and Drug Administration since 1950.
- Even those drugs that are approved are not universally effective due to individual reactions - the top ten highest-grossing drugs in the USA only help between 1 in 4 and 1 in 25 people who take them
- Of over 1,000 potential stroke treatments that had been ‘successful’ in animal tests, only approximately 10% progressed to human trials. None worked sufficiently well in humans.
- A review of 101 high impact basic science discoveries based on animal experiments found that only 5% resulted in approved treatments within 20 years.
Dangerous animal testing
- Vioxx, a drug used to treat arthritis, was found to be safe when tested in monkeys (and five other animal species) but has been estimated to have caused around 320,000 heart attacks and strokes and 140,000 deaths worldwide.
- Human volunteers testing a new monoclonal antibody treatment (TGN1412) at Northwick Park Hospital, UK in 2006 suffered a severe allergic reaction and nearly died. Testing on monkeys at 500 times the dose given to the volunteers totally failed to predict the dangerous side effects.
- A recent drug trial in France resulted in the death of one volunteer and left four others severely brain damaged in 2016. The drug, which was intended to treat a wide range of conditions including anxiety and Parkinson’s disease, was tested in four different species of animals (mice, rats, dogs and monkeys) before being given to humans.
- A clinical trial of Hepatitis B drug fialuridine had to be stopped because it caused severe liver damage in seven patients, five of whom died. It had been tested on animals first.
- Only one third of substances known to cause cancer in humans have been shown to cause cancer in animals.
Animals are different
- Animals do not get many of the diseases we do, such as Parkinson’s disease, major types of heart disease, many types of cancer, Alzheimer’s disease, HIV or schizophrenia.
- An analysis of over 100 mouse cell types found that only 50% of the DNA responsible for regulating genes in mice could be matched with human DNA.
- The most commonly used species of monkey to test drug safety (Cynomolgous macaque monkeys), are resistant to doses of paracetamol (acetaminophen) that would be deadly in humans.
- Due to the many important differences between monkeys and humans in brain structure and function, data collected from monkeys used in neuroscience research are misleading and of poor relevance to people, our recent analysis found.
- Chocolate, grapes, raisins, avocados and macadamia nuts are harmless in people but toxic to dogs.
- Aspirin is toxic to many animals, including cats, mice and rats and would not be on our pharmacy shelves if it had been tested according to current animal testing standards.
Animal experiments are cruel, unreliable, and even dangerous.
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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.
