The use of animal in experimental research causes an immense amount of suffering. Obviously it is suffering to the animals involved both in terms of physical pain and sensory deprivation. Less obviously, and usually ignored by the media, vivisection also causes a great deal of suffering to people. This happens firstly because drugs that are tested on animals and believed to be safe are subsequently found to harm humans and secondly because drugs that are found to be harmful to animals are denied to humans when they could in fact provide great benefit.
There is a great deal of difference in how different species react to different drugs. This is hardly surprising when there are even differences within a species. Some of us react differently to others to different chemicals.
Vivisection is a blind alley that consumes billions of pounds worth of fruitless research. Yes, some drugs may be found to be helpful to humans but they could have been found quicker and far cheaper by other methods. We need research to find cures for human ailments but we should be looking at using humane methods. Also, we need to invest in preventative medicine. We need to identify the habits that are harmful, such as smoking and excessive drinking and then make people aware.
We need also to look closely at the interaction between humans and their environment, in particular in the long term. What is the effect of breathing in a lifetime of car fumes in the urban environment? Or of breathing in a lifetime of the pesticides and herbicides that are spread over our fields in the rural environment?
We are not rats and we are not rabbits. If we are ever to control the scourge of the likes of cancer then we need to be imaginative and expansive in our research approaches. There are humane human-related alternatives to explore. For instance we should no longer waste billions on fruitless animal research but rather look for clinical feedback from the unfortunate sufferers - what might the causative agent or agents have been for specific illnesses?
Animal research is very profitable for the drug industry and because the drug industry controls our media through its advertising animal research is seldom questioned in the media. Occasionally though there are articles of dissent such as the following:
of article published in Guardian Thursday May 24, 2001
testing is a disaster
of people have been injured or killed by drugs that were found to be
safe for other species
do you feel is more important - the life of your child or the life of
a few rats? Such stark contrasts are common currency in the heavily
polarised debate about experiments on animals. On the one side the
misguided sentimentality of the animal rights campaigners, on the
other side the tireless pursuit of human happiness and health by the
But since those wide-eyed activists have put animals'
rights somewhere on the election agenda, you may be interested to
know that there is a totally hard-headed and rational case to be made
for saying that animal experimentation has been a scientific and
medical disaster. That far from saving lives, it has caused injury
and death to thousands and that time and again it has led both
researchers and legislators into a blind alley.
But surely, you
cry, we need animal experiments to discover how safe new drugs are
before we give them to humans? Well, the combination of fenfluramine
and dexfenfluramine, touted as the answer to a dieter's prayer a few
years ago, was extensively tested on animals and found to be very
safe. Unfortunately it caused heart valve abnormalities in humans. Or
how about the arthritis drug Opren? Tests on monkeys found no
problems but it killed 61 people before it was withdrawn. And as for
having to choose between rats and your child, Cylert, given to
children with attention deficit hyperactive disorder, was fine for
animals but caused liver failure in 13 children.
The problem is
not a new one, in fact it is blindingly obvious - animals are not the
same as humans, so drugs that affect them in one way may well affect
Now this is usually presented as a solvable
problem by researchers. We can get an idea of the mechanism from
animals and then fine-tune with humans, they say, but it doesn't work
like that. Species, even those that seem closely related, may
function quite differently at a molecular level, and there is no way
of predicting what the differences will be.
Rats and mice, for
instance, look pretty alike to us, but when it comes to something as
basic as whether a chemical causes cancer or not, the results may be
totally contradictory. Out of 392 chemicals tested for carcinogenic
effects at the American National Institute of Environmental Health
Sciences, 96 were positive in the rat and negative in the mouse or
vice versa. So which of those are harmful to humans? The institute
For 30 years they fed high doses of a range of new
chemicals to animals to discover if they caused cancer or other
damage. The results are recorded in blue books that take up 10 feet
of shelving in the institute. But ask how many of the substances
might produce tumours in humans at normal levels and no one knows. So
what about the ones that didn't harm rodents, how many of them might
harm humans? They don't know that either.
The lack of predictable
differences between animal and human reactions is something that has
bedevilled Aids research. Aids is a high profile disease with a lot
of research money available, so it surely makes sense to ignore
ethical objections and use chimpanzees. It is surely precisely
because their genome is identical to ours, give or take a few
percentage points, that they should yield more accurate results than
Well, no, actually. Out of approximately 100 chimps
infected with HIV over a 10-year period only two have become sick.
Chimp vaccine trials have proved unreliable too because they don't
show the antibody or cell-mediated response to HIV that humans do.
Animal experimentation has played only a small role in developing
drug treatments to the greatest plague of our time.
And the list
could go on. There are drugs that have been held back because they
caused dangerous reaction in animals, such as beta blockers and
valium, but then turned out to be safe for humans. Legislation to
halt the use of asbestos was held up for years because it didn't
cause cancer in animals, while the carcinogen benzene continued to be
used long after clinicians were worried because it didn't cause
leukaemia in mice.
All these examples, and many more, have been
written up in the specialist journals but until last year they had
been scattered. Then a man called Ray Greek, an American medical
doctor who specialised in the highly technical field of anaesthesia
collected them in a book called Sacred Cows and Golden Geese. He gave
a talk in London about it last night.
So was this scientific,
rational contribution to the debate about animal experiments warmly
welcomed, so medical research could be improved? Supporters of animal
experiments are always calling for more public discussion and
Of course not. It was ignored.
Jerome Burne is
editor of the monthly newsletter Medicine Today
4 March 2005.
Of mice, men and
By Robert Matthews
alerts suggest you don't have to be an anti-vivisectionist to doubt
the validity of animal testing.
Two huge industries affecting
the lives of millions of people are currently subject to big health
alerts. Concern over serious side-effects has cast a long shadow over
promising new painkillers, known as cox-2 inhibitors, developed by
the pharmaceutical industry. Evidence linking the drugs to an
increased risk of heart attacks led the US giant Merck to withdraw
its version, known as Vioxx, from the market last September, and an
investigation by the US Food and Drug Administration is currently
More recently, it was the turn of the UK food
industry, with the discovery of traces of a banned dye known as Sudan
I in a sauce made by Premier Foods, a leading UK supplier. In the
ensuing health scare, the UK Food Standards Agency found that
hundreds of products had been inadvertently contaminated by the dye,
which has been linked to cancer.
As the initial furore starts
to fade, both these health alerts are being seen primarily as wake-up
calls to business and regulators alike about the monitoring of
product safety. In the case of cox-2 inhibitors, the FDA looks set to
allow their continued use - albeit with much sterner safety warnings
to protect those most at risk from side-effects. Meanwhile, as shops
and supermarkets in the UK hunt down produce contaminated with Sudan
I, the FSA has continued to stress that the risks involved are "very
As well it might, for it is now clear that the
scientific case against Sudan I is far from
safety tests involved feeding rodents with levels of Sudan I
equivalent to human consumption of the sauce that triggered the scare
at a rate of three tonnes a day for two years.
Even after such
gargantuan exposure, the animals failed to produce consistent
evidence of a cancer risk. Other tests hinted at links with bladder
and liver tumours - but only after the dye was injected directly into
the organs of laboratory animals. While the scientific basis for both
the Sudan I and cox-2 inhibitor health scares may be contentious,
they have highlighted the need for close surveillance and prompt
action if problems emerge. At the same time, however, an even more
fundamental question has gone begging: just how reliable are animal
tests of product safety?
In the case of food safety, the
relevance to humans of animal tests involving colossal intakes or
direct injection into organs is clearly questionable. The use of
animals in drug safety testing raises altogether more complex issues,
however - as the cox-2 painkillers controversy shows.
with standard practice, Vioxx and the other drugs were tested in at
least two different types of animal before entering clinical trials
with humans. One of the main aims of such "pre-clinical"
testing is to detect signs of serious side-effects. In the case of
the cox-2 drugs, the animal testing failed to warn of the
cardiovascular effects that have prompted the current furore. Indeed,
several animal studies suggested the drugs would actually reduce the
risk of such side-effects. So what went wrong? Anti-vivisectionists
have been quick to voice their standard objection: animals are not
For all its familiarity, it is an argument that does
have relevance to the cox-2 inhibitors. In 2000, barely a year after
the launch of Vioxx, a study of more than 8,000 patients suggested
that those taking the drug faced a significantly increased risk of
heart attack. Yet subsequent animal-based research continued to
suggest such drugs could reduce the risk - prompting even Merck's
experts to concede in The American Heart Journal that: "The
relevance of these animal models in predicting effects in humans is
It is becoming clear that such uncertainty
extends far beyond one class of blockbuster drug.
journal Nature Reviews Drug Discovery last year published a review of
the evidence that animals are reliable predictors of toxic effects in
humans. The authors found that the evidence was "fragmentary",
with the few published studies pointing to "significant over-and
under-prediction of adverse effects from animal studies that varies
with the particular organ or system".
The review also
highlighted the lack of basic data needed for a scientific assessment
of animal testing, such as measures of predictive power and their
As it stands, the evidence suggests
animal tests may be unduly sensitive, wrongly predicting toxicity in
compounds that are in fact harmless to humans. If so, it would be an
ironic twist to the widely held belief that tests of animal are
crucial to the advancement of medicine, as they may in fact be
blocking the development of many safe and effective new treatments.
Yet in the absence of large-scale studies comparing drug responses in
animals and humans, it is impossible to know. Supporters and critics
of animal testing continue to trade anecdotes of individual successes
and failures, most published studies being so small they lack
statistical credibility. In another irony, the drive to minimise the
use of animals has compelled researchers to draw conclusions from
meagre evidence. For example, the studies designed to investigate the
effect of cox-2 inhibitors on cardiovascular risk typically involved
fewer than 20 mice.
The authors of last year's review called
on regulatory bodies and drugs companies to publish data currently
languishing in their files.
Whether the outcome will confirm
or confound the view that animals usefully predict human reactions
remains to be seen. What is clear is that, given the paucity of
systematic evidence, it is not necessary to be a placard-waving
protestor to harbour doubts about the validity of animal
The writer is visiting reader in science at Aston