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 naturally get many of the diseases that humans 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 cancer, Alzheimer’s disease, Parkinson’s disease, diabetes, stroke and AIDS in animals, none of these conditions have reliable and fully effective cures and some don’t even have effective treatments.

Unreliable animal testing

• 92% of drugs fail in human clinical trials despite appearing safe and effective in animal tests, often on safety grounds or because they do not work.
• Urology drugs have the lowest success rate (only 4% are approved after entering clinical trials) followed by heart drugs (5% success rate), cancer drugs (5% success rate) and neurology drugs (6% success rate).
• Our research has shown that using dogs, rats, mice and rabbits to test whether or not a drug will be safe for humans provides statistically little useful insight. Our study also revealed that drug tests on monkeys are just as poor as those using any other species in predicting the effects on humans.
• A recent study found that out of 93 dangerous drug side effects, only 19% could have been predicted by animal tests.
• Another study showed that over 1,000 potential stroke treatments have been “successful” in animal tests, but of the approximately 10% that progressed to human trials, none worked sufficiently well in humans.
• One review of 101 high impact discoveries based on basic animal experiments found that only 5% resulted in approved treatments within 20 years. More recently, we conducted an analysis of 27 key animal-based ‘breakthroughs’ that had been reported by the UK press 25 years earlier. Mirroring the earlier study, we found only one of the 27 “breakthroughs” had been realised in humans, and that was subject to several caveats.

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) is resistant to doses of paracetamol (acetaminophen) that would be deadly in humans.
• Chocolate, grapes, raisins, avocados and macadamia nuts are harmless in humans but toxic to dogs.
• Aspirin is toxic to many animals and would not be on our pharmacy shelves if it had been tested according to current animal testing standards.

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.