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ss nucleus - winter 2004,  Animal Experimentation

Animal Experimentation

Human experimentation on animals is a subject that literally evokes violent reactions: 'I don't think you'd have to kill too many [animal researchers]. I think for five lives, ten lives, 15 human lives, we could save a million, two million, ten million non-human lives…I am simply saying that [violence] is a morally acceptable tactic and it may be useful in the struggle for animal liberation.'[1] These comments by American surgeon and animal rights campaigner Jerry Vlasak led to him being banned from entering the UK. He uses extreme language, but surveys reveal that many people in the UK are uneasy about or opposed to the testing of new medicines on animals.[2]

The reality is that almost all modern drugs, vaccines, anaesthetics and many surgical techniques have been developed after tests on animals. No new drug is allowed to be tested on humans without animal safety tests, and the development of new drugs relies on an understanding of disease gained by animal research, increasingly making use of genetically engineered animals. What are the facts about animal experimentation, and how can we balance the value of human and animal lives?

Animal experiments in the UK

How many animals?

Currently, about 2.78 million animals are used in research in the UK each year.[3] The species most commonly used are shown in the following box:

Rodents (mostly rats and mice) - 84%
Fish, amphibians and birds - 12%
Other small animals (eg rabbits) - 1.5%
Large mammals (eg sheep, cows) - 2.1%
Dogs and cats - 0.3%
Monkeys - 0.15%

The most controversy is about the use of pet species, such as cats and dogs, and primates in experiments. The cats and dogs that make up 0.3% of the total number of animals used each year (8,250 animals per year) are all bred for research; no strays or unwanted pets can be used. Primates (around 4,000 per year) are mostly marmosets and macaques. Chimpanzees, orang-utans and gorillas have not been used in this country for over 20 years and their use is now banned. However, the use of primates in research is highly emotive: plans to build a primate experimental facility at the University of Cambridge were dropped in the face of protests by animal rights activists. At the other end of the scale, insects (such as fruit flies) and worms are used in very large numbers but this is not regulated at all.

Research areas

About one third of animals are used in drug development. Animal testing of medicines has been required by law in the US and UK for many years. In both countries, testing became a legal requirement after disasters involving drugs that had not been first tested on animals. In the US an early sulphonamide antibiotic killed 137 people in 1937, whereas UK legislation followed thalidomide, which caused 10,000 babies to be born with severe limb deformities around the world. In both cases animal testing would have revealed these serious side effects.

A further third of experiments are in basic biological and medical research, to discover how normal biology works and what goes wrong in disease. Increasingly genetically engineered mice are used in order to elicit precisely which genes are involved in a process or disease. This information is of great help in designing new drugs. Breeding these and other animals for research accounts for another 30% of the animals used.

The remainder of the animals (5%) are used for non-medical safety testing of substances ranging from industrial chemicals to household products. Until 1998 animals were used for testing cosmetics, but this is now banned. Aside from medical purposes, the Ministry of Defence uses animals in weapons testing, but publishes little information about numbers or species involved.

Regulation of animal experiments

Animal experiments are very tightly controlled in the UK. No one can touch a laboratory animal without a Home Office licence. Every new scientific project is reviewed by a vet, an ethics committee, and finally the Home Office, in a process taking several months, before any work can begin. All laboratory animals are held in approved facilities that are subject to surprise inspections. Detailed records about the treatment of every single animal have to be reported to the government. Animals are given anaesthetics and pain killers to alleviate distress, and any animal that is too distressed must be painlessly killed immediately to alleviate its suffering.Despite this, tight regulation doesn't make something ethically right. Furthermore, research is a global industry, and experiments that would not be approved in the UK can be performed in countries with lower animal welfare standards.

The majority of experiments are assessed to cause mild or moderate distress to animals; it is very difficult to obtain approval for experiments that cause severe distress to animals, although in some cases animal rights groups have argued that the grading of animal distress has been abused.[4]

The three R's

The guiding principles used in designing animal experiments are called the three Rs:

  • Reduce the number of animals used to a minimum
  • Refine experiments to make sure animals suffer as little as possible
  • Replace animal experiments with non-animal techniques where possible

1) Reduce

All animal experiments should be carefully thought through so that they answer the question being tackled. Bad experiments waste animal life and lead to no advance in knowledge, meaning that work has to be repeated. Experiments are designed with help from a statistician, so the results can be obtained using as few animals as possible. New techniques, such as bioluminescent imaging and magnetic resonance imaging can enable a disease process to be followed in the same animal over a period of time, vastly reducing the numbers of animals required to be killed at each stage of the experiment.

2) Refine

Research involving animals has to be designed so that any distress or suffering involved is kept to a minimum, and anaesthetics or painkillers are given after any surgical technique. If an experiment involves animals developing a fatal disease, such as cancer, it can be designed so that the animals are painlessly killed at an early stage of the condition, when they only show mild symptoms, instead of waiting until they have advanced disease. Old fashioned safety tests, like the LD50 test, that involved finding the dose of a drug or chemical which would kill half the animals being tested, have been replaced by tests in which lower doses are given in a manner that allows safe doses to be predicted.

3) Replace

Much major progress in biological research has not involved animals in the last 20 years. This has meant developing non-animal alternatives, for example in safety testing the effect of chemicals on the skin. However, animals remain the only system in which some biology can be studied. For example, the spread of tumours and safety testing of certain new drugs can only be done in animals. It looks likely that some areas of biomedical research will require animal experiments for many years to come. For example, stem cell therapy requires animal tests to work out whether it can be safely performed in humans.

Are animal experiments ethical?

Even with all these safeguards in place, many people feel either uneasy about or hostile to animal experiments. There are two conflicting contemporary views on animal experiments:

Animals have rights - experimentation is cruel exploitation by humans

The animal liberation movement sees humans as just one of many animal species, with no grounds to claim that we are superior to any other kind of creature. Following this argument, animal experiments are regarded as 'speciesist', discriminating unreasonably on the basis of species. This is considered just as offensive as racism or sexism, amounting to cruel treatment driven by prejudice. Humans should experiment on other humans and not abuse weaker species. More background on this view is found in a recent CMF File.[5]

Animals are owned by humans, so there are no problems with experimentation

The opposing view is that humans own animals, which are intrinsically inferior. Animals have value only because they are useful to humans and, as a result, there are no limits on what humans can do to animals. This view justifies not only animal experimentation, but poor living conditions for a large number of animals in industrial farming, as well as the destruction of ecosystems and entire species by agriculture and industry.

A Christian perspective

As with many areas of biology and medicine there are no biblical proof texts that give us a simple answer to the ethics of animal experimentation. However, we can find some clear starting points about the relationship between humans and animals.

Humanity has unique value from a relationship with God

In the past people have argued that humans are superior to animals because of differences in our biology. For example, only humans, it was said, have language, creative thought, etc. As humans are superior, experiments on animals are justified. We now know that almost all aspects of human behaviour and experience can be found to some extent in animals, including complex social behaviours, making tools to solve problems, creative reasoning and language. Instead, to understand the meaning and value of humanity we need to go back to the revealed truths of the Christian faith, which can neither be inferred from nor tested by biological science.

Man – both male and female – is made in the image of God, and this marks us out from the rest of creation, giving us unique worth and moral value: 'Let us make man in our image, in our likeness'.[6] In particular, we see the supreme testimony to the value and significance of our species in the fact that God became man in Jesus Christ, and lived, died and rose again in order to restore humanity to a relationship with God. In Jesus we can see clearly what the book of Genesis meant when it says that man, as distinct from animals, is made in the image of God.

We are not just clever apes, winners of an evolutionary lottery, destined to strive against each other and other species in the unending battle of natural selection. Our lives, both as individuals and as a species, matter because God calls each of us by name, loves us and challenges us to love both him and each other.

Humans as caretakers of God's creation

Being made in the image of God also gives man a unique responsibility as his stewards in the natural world. Genesis 1:26 goes beyond describing humanity to assigning responsibility: 'Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground.' As in the parable of the talents,[7] God will weigh up the decisions we make about how we use the resources he has given us. Humans in the 21st century have powerful biomedical technologies and a greater awareness than ever before of the complexity and fragility of the natural world. In the language of the parable, we have been entrusted with a full ten talents worth of resources. It is up to us to use these wisely, in a way that will please God.

The text of Genesis 1:26, calling us to 'rule over' the animal kingdom, has been used to justify exploitation of the animal world, crushing nature to bring us food, power and wealth. Such a view is a gross distortion of what our relationship with animal life is meant to be. Man has been entrusted with ruling the natural world, but it is God's property, an expression of his wisdom and creativity. The psalms portray God as the one who sustains both human and animal life and how both humans and animals are interconnected with the natural world. God 'makes springs…give water to all the beasts of the field; the wild donkeys quench their thirst. The birds of the air nest by the waters; they sing among the branches…these all look to you to give them their food at the proper time...May the Lord rejoice in his works'.[8] In the great description of God's wisdom that reduces Job to silence, God is seen as the one who delights in each animal and bird.[9] Our attitude to the animal world should surely reflect God's.

Is it fair for one species to be able to rule over others as humans do over animals? Clearly the conduct of humans means we don't deserve to hold such a position, and animals certainly don't deserve much of the treatment suffered at our hands. The created order yearns for the day when humanity will be rescued from the destructive power of our sin, our inability to care either for God or his world.[10] Christianity is not based on our notions of fairness but on God's wisdom and grace. When we consider what ruling means to the Christian, we might find it more acceptable. In John 13:1-17 where Christ washed his disciples' feet, he defined being a ruler as being a servant; we may rule the natural world but it is not ours to abuse and destroy - rather it is entrusted to our care.

We need to question what our treatment of the earth's ecosystem, the welfare of animals in factory farms, the extermination of thousands of animal species, as well as animal experimentation says about the way we rule the natural world. We also need to proclaim that it is possible to live in balance with a fragile planet, raise farm animals in good conditions, and protect the habitats of endangered species. On the issue of animal experimentation we are called to avoid the simple solutions of saying all experiments are ethical or all experiments should be banned, until we have thought through and agonised over the arguments. The Christian perspective hands us the responsibility to decide how we can balance relieving suffering for humans, who are uniquely valuable in the sight of God, with the welfare of animals that God sustains and takes delight in.

Tough questions

There is no simple answer to the question of whether animal experiments are ethical. Here are two examples of the issues we must consider in building our response to animal experimentation.

Drug development

Can we justify treating humans with new drugs without looking for dangerous side effects in animals?

Not to do this places the lives of patients in early clinical trials at increased risk. As discussed above, there have been disasters following failures to carry out appropriate animal tests; these have made animal testing of new drugs a legal requirement. Humans are of more value than animals because of God's own image reflected in us, but animals matter and their suffering should be minimised. Drug safety testing is improving, and the latest mathematical research investigating new ways of modelling drug levels in animals may reduce the number of animals involved in testing. Abandoning the old LD50 test, which required increasing doses to a level where half the animals died, has substantially decreased the suffering of animals involved in tests. There seems no way to avoid using some animals in drug testing at present, but we should support efforts to refine and replace tests wherever possible. It is ironic that chemotherapy drugs developed using animal testing and refined in clinical trials on patients are now used to benefit animals, for example by vets treating dogs with lymphoma.

Basic science

Can we justify animal experimentation in 'curiosity driven' basic scientific research with no direct medical benefits? Many animals are used for such purposes. Some experiments may lead to improved treatments in the future through a better understanding of animal physiology and genetics. However, most experiments of this sort have little relevance to new drugs or treatments.

The degree to which animals suffer is key in assessing this type of work. In 'mild' experiments, animals have treatments that cause no or minimal symptoms and are then killed painlessly. These animals may be significantly better treated than many farm animals. If we allow animals to be farmed to produce meat, we may consider it acceptable to 'farm' laboratory animals for knowledge instead of food.

In other experiments significant animal suffering is inevitable. It seems difficult to justify any experiments causing moderate or severe distress to animals that do not have a very direct benefit to human health. All scientific experiments have to be rigorously designed. Bad science is a needless waste of animal life and should be deplored.


Animal experimentation raises big questions and provides no simple answers. After much consideration, my own personal position can be summarised by saying that some experiments are clearly justified, whilst others are clearly not. This leaves a significant section where I am still not sure.

In grappling with dilemmas such as these we are confronted by the difficulty of the task entrusted to humankind by God, and are driven to ask for divine wisdom in making what are often uncomfortable decisions. To maintain a Christian position in this debate will result in hostile criticism from those with extreme views, both for or against. Nevertheless, I believe this is what we are called to do.

  1. Laville S. Banned activist defends violence. Guardian 2004; 28 August
  2. Guardian/ICM Monthly Poll; January 2001.
  4. Curtis P. MPs urge inquiry into Huntingdon xenotransplantation. Guardian 2003; 11 November
  5. Misselbrook D. Speciesism. CMF Files 26. London: CMF, 2004
  6. Gn 1:26
  7. Lk 19:11-26
  8. Ps 104:10-31
  9. Job 39-41
  10. Rom 8:19-22
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