‘Models’, ‘test systems’, ‘research tools’, ‘products’; euphemisms for animals. They are called anything but living, feeling, sentient creatures.
Animal ‘models’ are not predictive
Open up a rat, a dog, a pig and a human and you will find much the same terrain, but with many intricate differences. It is precisely these differences which have an impact when it comes to assimilating drugs. For example, rats, the species most commonly used in vivisection (1), have no gall bladder and excrete bile very effectively. “Many drugs are excreted via bile, so this affects the half-life of the drug,” explain Ray and Jean Greek.
“Drugs bind to rat plasma much less efficiently. Rats always breathe through the nose. Because some chemicals are absorbed in the nose, some are filtered. So rats get a different mix of substances entering their systems. Also, they are nocturnal. Their gut flora are in a different location. Their skin has different absorptive properties than that of humans. Any one of these discrepancies will alter drug metabolism.
” These differences are on a gross level. Medications act on a microscopic level, initiating or interrupting chemical reactions that are far too small for the human eye to observe. “We differ on the cellular level and molecular level and, importantly, that is where disease occurs,” the authors explain. “The cells of chimps are very similar to the cells of humans, but the spatial organisation of the cells is vastly different.”
Even those who favour the animal model admit its unpredictability among their peers. Dr Ralph Heywood, director of Huntingdon Research Center in the United States, says: “The best guess for the correlation of adverse reactions in man and animal toxicity data is somewhere between five and 25%.”
…a game of chance
Dr Herbert Hensel, Director of the Institute of Physiology at Marburg University, goes further: “In the opinion of leading biostatisticians, it is not possible to transfer the probability predictions from animals to humans. At present, therefore, there exists no possibility at all of a scientifically based prediction. In this respect, the situation is even less favourable than a game of chance.”
Even the most widely respected textbook on animal experimentation states: “Uncritical reliance on the results of animal tests can be dangerously misleading and has cost the health and lives of tens of thousands of humans.”(2) The best-known example of this is thalidomide. Mothers who took this drug to relieve morning sickness gave birth to children with shocking deformities, with most lacking developed limbs.
Animal tests had not predicted this.The first recorded case of side effects occurred on Christmas Day 1956, but in 1957 the drug was released anyway.
(1) Vivisection refers to the dissection of, or any cutting or surgery upon, a living animal. More generally, it is used to describe any invasive experiment upon living animals, or any live animal testing, typically for the purpose of physiological or pathological scientific investigation.
(2) Svendsen, Per, “Laboratory Animal Anaesthesia”, in Handbook of Laboratory Animal Science (P. Svendsen and J. Hau, editors), CRC Press, vol. 1, p. 4.
Testing on animals only benefits big business
by Dr Ray Greek MD
Many people are morally opposed to experiments on animals, even if they are of supposed medical benefit. Such people are often portrayed as wishing to sacrifice medical progress to avoid animal suffering. The government and the media dismiss their concerns by labelling them ‘anti-science’: a convenient, but totally false, stereotype. But what if there were no medical benefits from experiments on animals?
What if they were actually an obstacle to medical progress: misleading scientists, harming patients by their unreliability and wasting precious funds that would be better spent on patient-oriented research?
If that were really the case, then stopping animal experimentation would be in everyone’s best interests: truly a win-win situation!
Clearly, a careful study of the medical literature is required in order to make an informed judgement. After completing our medical and veterinary training, my wife and I spent ten years doing just that before we wrote our first book, Sacred Cows and Golden Geese: the Human Cost of Experiments on Animals. We reviewed thousands of scientific papers and examined the history of medicine at length.
We found precious little evidence of human benefit but abundant evidence of human harm. The common claim that “all medical breakthroughs rely on animals” strikingly demonstrates how repeated lies can be perceived as truths.
Dr Albert Sabin, the inventor of the polio vaccine, regretted that the vaccine was “long delayed by the erroneous conception of the nature of the human disease based on misleading experimental models of the disease in monkeys”. Heart-valve replacements, penicillin and many other therapies were similarly delayed because of misleading test results in animals. People died as a result of those delays.
Smoking cigarettes and eating lots of cholesterol were given the thumbs-up by animal experimentation. Probably no two mistakes have cost as many lives. Now millions of women on hormone replacement therapy are at twice the risk of breast cancer and heart disease, thanks to tests in monkeys which predicted the opposite. How many more people have to die before we admit there is a problem with animal testing?
It is commonly known that cancer, heart disease and stroke are the leading causes of death in the West. But many people would be surprised by one of the next biggest killers: side effects of prescription medicines. Adverse drug reactions kill over 100,000 people a year in the US and almost as many in the UK. That is more than all illegal drugs combined.
Clearly, there is something very wrong with the way drugs are screened for safety before being sold. One of the major problems is testing on animals. Animals metabolise drugs differently from humans: thus substances which are safe for dogs or rats may not be safe for people. For example, Rezulin (for diabetes) passed animal tests with flying colours but killed thousands of people before it was withdrawn in 2000.
Penicillin – such a valuable drug for humans – kills guinea pigs and hamsters. Experiments on rats cannot predict which substances will cause cancer in mice, and vice versa – so how on earth can they predict which will cause cancer in humans?
Overwhelming evidence shows that testing drugs on animals is meaningless for humans, with a successful prediction rate for side effects of only 5-30%. For example, in a review of drugs withdrawn from the market (1960-90) only four out of 24 side effects were predicted by animal tests. In another review only six of 114 human toxicities had animal correlates.
Tossing a coin would predict drug safety better than animal tests – even a former Director of Huntingdon Life Sciences (1) admits that! Professor Andre McLean of University College, London said: “Yes, I think it is very clear to all of us who are engaged in the business of assessing toxicity data that…very often the carcinogenicity studies are a waste of everybody’s time and a fearful waste of animals. They are conducted partly because we are not sure what to do instead, and partly because they are a political gesture and a very miserable one at that.”
Drugs would be much safer for patients if they were tested not in animals but in human tissues, human DNA chips, computer models of human organs and finally in risk-free micro-dose studies in human volunteers. We are entering an era of personalised medicine, where individually tailored prescribing will make drugs much safer and more effective.
The great breakthroughs in science that have given us all the medical advances we enjoy today have actually come from ethical, human-based research – most notably astute clinical observation, epidemiology (population studies), autopsies and in vitro (test-tube) research, including the use of human tissue. Anaesthetics, antibiotics, aspirin, beta-blockers, pacemakers and many other great discoveries owe nothing to animals and everything to human ingenuity, careful studies of patients and brave (or foolhardy!) self-experimentation by pioneering scientists.
Computer modelling along with other technological advances like ct, pet and MRI scanners will complement the traditional research methods and give us knowledge about human disease that animal models never could and never will. If animal experiments are so inferior to human-based technologies, why do they persist?
There are many reasons, including scientific tradition and conservatism, but chief among them is money. Animal experimentation is a multi-billion-pound business. Universities, animal breeders, suppliers of cages and equipment, and pharmaceutical companies all profit. Sales of laboratory mice alone amount to £200 million per year. Many doctors and scientists oppose animal testing, but very powerful vested interests ensure its continuation.
The major reason new drugs are still tested on animals is to protect companies in court when people are injured or killed by adverse drug reactions. Pharmaceutical companies admit, in private and sometimes even in public, that animal testing is ineffective but is done because it provides liability protection.
Juries are easy to convince that by conducting multitudinous animal tests of the offending drug, the company did ‘due diligence’ and had no idea that the drug would kill people. Instead of paying millions of pounds in compensation, they get away with paying thousands. Yet as long as drugs are tested on animals, serious side effects in humans are inevitable. As to finding cures for our most dreaded diseases, it is vital that we abandon animal experiments if we expect to see any progress here.
In 1998, Dr Richard Klausner, Director of the US National Cancer Institute (NCI), admitted, “The history of cancer research has been a history of curing cancer in the mouse. We have cured mice of cancer for decades – and it simply didn’t work in humans.” The NCI believes we have lost cures for cancer because they were ineffective in mice. For many types of cancer and for diseases like AIDS, prevention is not just better than cure – it is the only cure. Animals cannot help us to identify risk factors or how to prevent disease – such knowledge can only be learned from humans.
Twenty years and millions of pounds have been spent on AIDS research in chimpanzees, but the resulting vaccine has failed in people – leaving 8,000 high-risk volunteers in the trial unprotected. Animals do not suffer from the same diseases as humans, and in order to recreate some of the symptoms for study they have to be physically or chemically damaged. Very often, any treatments developed in the animal are invalid for humans because the underlying causes of the symptoms are so different. Curing heart failure induced by cutting a dog’s aorta will not help to cure heart failure caused by a build-up of cholesterol in human arteries.
Yet the UK government recently approved Cambridge University’s controversial primate brain laboratory – overturning the conclusion of its own public inquiry that such research is not in the national interest. Monkeys do not suffer from Alzheimer’s or Parkinson’s – it is in human tissue that we will find the answers to these diseases. Everything we know about them has been learned from studying patients and their tissues, even though brain banks and other vital human-centred facilities are chronically under-funded and under-valued.
Large sums of money spent experimenting on monkey brains will mean less money is available for scientists studying human brains. Worse still, findings from marmoset/macaque monkeys are likely to mislead neuroscientists as they have in the recent past, often with tragic consequences. For example, dozens of treatments for stroke have been developed in primates but all of them have failed in humans and harmed people in clinical trials.
The public has long been sold the idea that cures for human disease will be found via animals. It is time the public knew that this is an expensive and dangerous lie. Until animal experiments – which are “utterly futile” according to Professor Sir Michael Rawlins, chair of the National Institute for Clinical Excellence – are abandoned in favour of state-of-the-art medical research, we will not see cures for the illnesses that plague us, and will continue to suffer the consequences of useless and outdated research.
‘Safe’ for human use
The following are some examples of pharmaceutical drugs which had been deemed safe for human use after extensive animal testing, but which were later found to cause serious side effects.
Use of this drug for treating heart failure led to 20% of patients developing thrombocytopenia (lack of blood cells needed for clotting), despite a comprehensive program of animal studies in mice, rats, hamsters, guinea pigs, dogs and rhesus monkeys. Some of these [human] patients died.
Birth control pills
These are known to cause life threatening blood clots in some women, yet scientists have still not been able to reproduce this finding in animals. In fact, dog testing predicted that the pill would decrease the likelihood of clotting.
This antibiotic caused life threatening anaemia in humans. Chloramphenicol is an example of a drug whose effects vary from species to species: dogs do well with it, cats die from it, cows tolerate it but horses do not. It is so toxic to susceptible humans that its use has been outlawed in animals used for food. The tiny amount consumed from ingesting a hamburger made from a treated cow will cause death in such a person unless they receive a bone marrow transplant.
This anti-diarrhoeal passed tests in rats, cats, dogs and rabbits. It was pulled off the shelves all over the world in 1982 after it was found to cause blindness and paralysis in humans.
This synthetic oestrogen was designed to prevent miscarriage, but it did just the opposite by increasing the rate of spontaneous abortions, premature births and neo-natal deaths. No human trials were done; all the safety data was collected from animals.
This heart drug was withdrawn after causing serious side effects in an estimated 7,000 victims, 23 of whom died. It had been tested for six years in mice, rats, dogs and monkeys and when introduced on the market was “particularly notable for the thoroughness with which its toxicity was studied in animals, to the satisfaction of the authorities”.(1) Even long after the drug was withdrawn, scientists failed to reproduce these results in animals.
This antibiotic progressed through animal testing, only to cause seizures and psychosis when used by humans.
A medication used to treat asthma, it proved devastatingIy toxic to humans in the amounts recommended based on animal studies. In Great Britain alone, 3,500 asthmatics died from using the medication.
This treatment for migraine led to severe scarring of the heart, kidneys and blood vessels in the abdomen, although scientists had been unable to reproduce these effects in animals.
This treatment for rheumatism and arthritis killed 61 people and caused 3,500 adverse reactions. Withdrawn in 1982, the drug had been tested on monkeys and other animals for nine years with no adverse side effects.
This drug, found in many common cold and flu remedies, was banned by the FDA in the US after it was linked to causing between 200 and 500 strokes in young women a year.
This arthritis drug was withdrawn from the market when patients suffered kidney toxicity. Prior to its release, researchers said this about the animal tests: “…excellent safety profile. No cardiac, renal [kidney] or central nervous system [side effects] in any species.”
This drug, used to treat and prevent breast cancer in women, caused liver tumours in rats but not in mice or hamsters. The drug has been shown to be harmless to the developing foetus of rabbits and monkeys, but to cause bone abnormalities in rat foetuses. One of the side effects is nausea and vomiting, but this was not predicted in animal studies, even though high doses were tested in dogs – the species considered most predictive of vomiting in humans.
The drug has also been implicated in uterine cancer, blood clots, memory loss, absence of periods, and eye damage such as cataracts.
This arthritis drug killed 14 people and caused many more to suffer. (1) Br Med J, 1983, Jan 15
From Sacred Cows and Golden Geese – the Human Cost of Experiments on Animals
As well as animal tests allowing unsafe drugs onto the market, the flip side is that human health is also compromised when drugs which may be beneficial to humans are prevented from being released.
Most drugs have side effects, some of which are more acute than others, but many useful medications used to save lives would not have reached clinical trials if they had first been tested on animals.
Arguably the most successful drug ever, causes birth defects in mice and rats and results in such extensive blood abnormalities in cats that they can only take 20% of the human dosage every third day. Another painkiller, ibuprofen, causes kidney failure in dogs, even at low doses. Other prescription drugs were initially unavailable to people because animal studies predicted side effects not found in humans. They include:
Are used in a variety of conditions, ranging from brain tumors to skin diseases. They have been shown to cause cancer in some rodents, despite their being used safely by humans for years.
This contraceptive was barred from release in the US in 1973 because it caused cancer in dogs and baboons.
This anti-rejection drug was almost shelved before it proceeded to clinical trials. After experimenting on dogs, researchers said animal toxicity was too severe to proceed to the clinical trial stage.
Mice, rats and hamsters suffer liver damage from this diuretic, but humans do not. It is widely prescribed for the treatment of high blood pressure and heart disease.
This medication, commonly used for treating tuberculosis, caused cancer in animals.
The release of penicillin was delayed when its discoverer, Alexander Fleming, put it to one side because it did not work in rabbits. This is because rabbits excrete penicillin in their urine. Only when Fleming had a sick human patient and nothing else to try, did he administer penicillin – with excellent results.
The release of this gastrointestinal medication was delayed for 12 years because of an effect in animals which did not occur in humans.
This popular antibiotic caused birth defects such as limb malformations in the offspring of rats.
Animal ‘test systems’
by Jessica Sandler
Most Americans, when asked to consider how the US Environmental Protection Agency (EPA) spends their tax dollars, don’t typically picture dogs being shoved into metal chambers and forced to eat or inhale pesticides until they go into convulsions. Nor do they imagine rows of rabbits in full-body restraints vainly attempting to save themselves from the industrial solvents that researchers swab into their eyes.
But the sad reality is that this horrific treatment of animals happens routinely at the direction of the EPA. These tests are an enormous waste of lives and dollars. Outdated, unreliable, and cruel animal tests required by the EPA won’t protect you or your children from chemicals, and they haven’t for a long time. Look at the agency’s record.
In ten years, the EPA has not used its authority under the Toxic Substances Control Act to ban a single toxic industrial chemical. The chemical manufacturing industry has long supported the EPA’s near-exclusive reliance on animal tests, for a number of reasons. Any required testing means that products are safe from regulation for years while they are tested and re-tested on animals.
Here’s how they do it: If a chemical is shown to cause cancer or have other harmful effects during animal testing, industry representatives claim the results aren’t applicable to humans. Saccharin, recently removed from the federal list of cancer-causing chemicals, is an example.
In the late 1970s, huge doses of saccharin caused bladder cancer in rats, and the sugar industry had a field day. Now, two decades later, government scientists have been forced to admit that the results of animal tests just aren’t applicable to humans.
At the same time, though, company officials happily rattle off the results of EPA-required studies that indicate their chemicals are not harmful. In these cases, companies laud the predictability of animal studies and claim that their products are safe for humans.
The EPA’s addiction to animal testing is so strong that even when evidence from human epidemiological studies implicates a chemical in the spread of a disease, the results are ignored by the EPA for the sake of conducting more and more animal studies. For years, population studies have shown that arsenic in drinking water causes cancer in humans. Yet the EPA dragged its institutional feet for more than 20 years while thousands of animals were killed in tests that attempted to reproduce the effects already seen in humans.
The EPA’s callousness toward animals is best revealed in its “Good Laboratory Practices” manual, which refers to living, breathing, feeling beings as “test systems”.
The agency’s indifference to animal suffering is vividly demonstrated by the fact that it allocates virtually none of its US$500 million annual research budget to developing non-animal test methods. Instead, the EPA erects roadblocks at every turn, refusing to use internationally accepted non-animal tests that are more sensitive and less subject to manipulation.
It demands that the validity of non-animal tests be rigorously proven through years of practice and refinement even though not a single animal test method has ever been “validated” as to its reliability and relevance to humans much to the detriment of the environment and human health.
Sadly, many EPA officials aren’t aware of their own agency’s outdated animal testing practices and claim that it hasn’t required such tests in years. If its left hand doesn’t know what its right hand is doing, how can the EPA possibly protect us?
While animals are choking on chemicals in EPA-mandated tests, the EPA is choking on its own inertia and inaction. In the interest of ethics, good science, and the protection of our children, the EPA must stop poisoning animals.
Jessica Sandler is a former OSHA health and safety official, is the federal agency liaison for PETA.