Those who would seek to abolish animal research often claim that the use of
animals in biomedical research is unnecessary because information can be obtained
by alternative methods, such as test tubes and computers.
What is often not realised is that scientists have strong ethical, economic
and legal obligations to use animals in research only when absolutely necessary.
A lot of effort goes into trying to reduce the numbers of animals used, and
trying to develop new methods to replace animals. As a result, the number of
laboratory animals used annually in this country has almost halved in the last
20 years.
Non-animal methods - tissue culture, computer modelling, studies of patients
and populations - are very widely used. In fact, only about five pence in every
pound spent on medical research goes on animal studies. The word alternatives,
often used to describe these non-animal methods, can lead to confusion because
these methods are generally used alongside animal studies, not instead of them.
All these techniques have their place, and it is rarely possible to substitute
one for another.
There are stages in any research programme when it is not enough to know how
individual molecules, cells or tissues behave. The living body is much more
than just a collection of these parts, and we need to understand how they interact,
how they are controlled. There are ethical limits to the experiments that we
can perform in people, so the only alternative is to use the most suitable animal
to study a particular disease or biological function.
It is illegal to expose patients to new medicines without being confident
that they are likely to benefit and not be seriously harmed. Treatments must,
therefore, be tested first in animals to establish their probable effectiveness
and safety. They are then tested on human volunteers. The process is not perfect
but testing in whole animals is by far the best way to protect people.
For example, it is difficult to even imagine what range of test tube techniques
or the complexity of computer systems that would be necessary to mimic the amazing
events that occur during the development and birth of a new baby. With present-day
technology, and even in the foreseeable future, this is simply not possible.
By contrast, appropriate whole animal tests can detect potentially harmful effects
of new treatments on foetal development and other events during pregnancy. Thus
another thalidomide disaster is most unlikely.
No one wants to use animals unnecessarily or to cause them unnecessary suffering.
The guiding principles in animal research today are called the Three R’s:
- Replacement, to replace animal procedures with non-animal techniques wherever
possible
- Reduction, to minimise the number of animals used
- Refinement, the way experiments are carried out, to make sure animals suffer
as little as possible
All animals involved in scientific research are very closely regulated. The
most important document governing this work, the Animals (Scientific Procedures)
Act 1986, is a benefit analysis which must be applied before any research project
involving animals can proceed. Thus the costs, in terms of potential animal
suffering, must be weighed against the potential benefits of the research. The
Act requires that animal procedures:
- take place in designated premises (which must obtain a certificate of designation)
- form part of an approved programme of work (which must obtain a project
licence)
- are conducted by competent persons (who must obtain a personal licence)
Licences are only granted if:
- the potential results are important enough to justify the use of animals
(the benefit analysis)
- the research cannot be done using non-animal methods
- the minimum number of animals will be used
- dogs, cats or primates are only used when absolutely necessary
- any discomfort or suffering is kept to a minimum by appropriate use of anaesthetics
or pain killers
- researchers and technicians conducting procedures have the necessary training,
skills and experience
- research premises have the necessary facilities to look after the animals
properly (laid down in a Home Office Code of Practice)
To ensure that all animal based research is done according to these controls,
the Home Office employs a team of inspectors, who are all qualified vets or
doctors. On average, they visit each research establishment eight times a year
usually without prior notice. In addition, at each establishment a vet must
be on call at all times.
During the development of new chemical entities, medicines must pass extensive
screening by test tube methods before they are allowed to be exposed to animals.
These tests give valuable information about how the drug reacts in the living
body, and often show up previously unpredicted side effects. For instance, the
route of administration is important: a drug given by mouth may be altered by
digestion, becoming less effective or more toxic. This is the sort of problem
that will not be apparent from test tube results, but will only show up in a
living body.
The animal tests are designed to reveal potentially undesirable effects such
as liver damage, raised blood pressure, nerve damage, or damage to the foetus.
The results of the animal studies will give a strong indication of what the
effects in people are likely to be. It is obviously important, and is required
by law, to find out about potential problems before drugs are given to human
volunteers and patients in clinical trials.
Human clinical trials will involve testing a drug on 3-5000 human volunteers
and patients. If a side effect affecting say 1 in 10,000 patients does occur,
this could only show up after the product is on the market - it is unlikely
that any such problem could have been spotted before. This does not invalidate
the research data gained from the work with animals.
The number of drugs withdrawn from the market is also consistently overstated
by animal rights activists, who often refer to "an endless list".
In fact, of the 2,000 types of drug on the market, less than 40 have been withdrawn
in the UK, US, France or Germany. This indicates a success rate of at least
98% for drug testing procedures. In fact, only 10 of these drugs have been withdrawn
in all four countries.
All mammals are descended from common ancestors, and one result of this is
that humans are biologically very similar to other mammals. All mammals, including
humans, have the same organs - heart, lungs, kidneys, liver etc. - performing
the same functions and controlled by the same mechanisms, via the blood stream
and nervous system.
Of course there are minor differences, but these are far outweighed by the remarkable
similarities. The differences can give important clues about diseases and how
they might be treated.
Vitamins and hormones identified by animal experiments were found to have similar
functions in people. The following animal hormones have all been used successfully
in human patients:
- insulin from the pancreas of pigs or cows
- thyrotropin from cows pituitaries
- calcitonin from the parathyroid gland of salmon
- adrenocorticotrophic hormone from pituitaries of farm animals
- oxytocin and vasopressin from pig posterior pituitary glands
No one will claim that animals are identical to humans but in the struggle
to find new cures and better treatments, animals remain the closest model to
human beings.
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