ethics of animal experiments in 3 steps by stijn bruers

7/30/2019 Ethics of Animal Experiments in 3 Steps by Stijn Bruers

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The ethics of animal experiments

in 3 steps

Stijn Bruers

Bite Backaug-2013


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The 3 steps

Step 1) Animal experiments are scientifically

unreliable: animal models lack predictability

for humans

Step 2) Animal experiments are ethically

unjustifiable: too much loss of well-being

Step 3) Animal experiments are ethically

unjustifiable : too much violations of basic

rights


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Step 1: scientifically unreliable

Effect humans

Yes No

Effect

animals

Yes True positive test False positive test

No Falss negative test True negative test

Imagine animals were notsentient. Do animalexperiments still have value?

Applied biomedical research for human purposes: barely

Fundamental research: yes

Problem 1: too many false positive and false negativetest results

Too low predictive value for humans


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False positive tests Chocolate? Lethal for dogs!

Safe medicines harmful for animals. E.g.: aspirin,

Many substances carcinogenic for mice but not forhumans

Positive predictive value: if there is an observedeffect in animals, how big is the probability thatthe effect will be observed in humans?

Often < 50% probability!

Delay of development of good products andmedicines


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False negative tests No observed effect in animals, but effect in humans

E.g.: Softenon (thalidomide), Vioxx, cyclosporin,TGN1412, Tested safe in animal experiments,

dangerous/lethal for humans Smoking: lung cancer in humans, not in mice

Epidemiological research instead of animal experiments

Negative predictive value: if there is no observed effectin animals, how big is the probability that the effect

will notbe observed in humans? Often < 50% probability!

Allows dangerous products on the market


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Problem 2: which species?

Discovery of first antibiotic: penicillin (A.

Fleming, 1928)

No effect in rabbits (false negative)

Good result with dogs (true positive)

Dangerous and lethal for rats, hamsters and

guinea pigs (false positive)


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How to predict the correct lottery number?

Most of the time there is a winner, so look at

the collection of all lottery players?

No prediction possible

Which player?


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Problem 3: how to cause a human disease in

healthy animals?

E.g. MS, Parkinson,

Procedure is often merely harming animals

such that they acquire some symptoms (e.g.

shaking) instead of the disease


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No anecdotes! No cherry picking of examples

But:

Statistical analysis of collection of studies (meta-

analysis)

Blind peer reviewed

Critical, impartial

Reviews of systematic reviewsnew (only last decade),

increasing recognition of importance


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Reviews of systematic reviews (last decade) Anisimov V.N., Ukraintseva S.V., Yashin A.I. (2005). Cancer in rodents: does it tell us about cancer in humans? Nat

Rev Cancer5:807-819.

Greek, R. and Menache, A. (2013). Systematic Reviews of Animal Models: Methodology versus Epistemology. Int JMed Sci10(3):206-221.

Hackam D. G., and D. A. Redelmeier. (2006). Translation of Research Evidence from Animals to Humans.JAMA 296:1731-1732.

Knight A., Bailey J., Balcombe J. (2006) Animal carcinogenicity studies: 1. Poor human predictivity.Altern Lab Anim34:19-27.

Knight, A. (2007). Systematic reviews of animal experiments demonstrate poor human clinical and toxicologicalutility.ATLA 35:641-659.

Knight, A. (2008). Systematic reviews of animal experiments demonstrate poor contributions toward humanhealthcare. Rev. Recent Clin. Trials 3:89-96.

Mestas, J and Hughes, CCW, (2004). Of mice and not men: differences between mouse and human immunology.The Journal of Immunology, 172: 5.

Perel P, Roberts I, Sena E, Wheble P, Briscoe C, Sandercock P, Macleod M, Mignini LE, Jayaram P & Khan KS (2007).Comparison of treatment effects between animal experiments and clinical trials: systematic review. British Medical

Journal334:197-203. Pound P., Ebrahim S., Sandercock P., Bracken M.B., Roberts I. (2004). Where is the evidence that animal research

benefits humans? British Medical Journal328:514-517.

Seok, J Shaw Warren, H et al, (2013). Genomic responses in mouse models poorly mimic human inflammatorydiseases. PNAS 110(9): 35073512.

Shanks, N. Greek, R. Greek, J. (2009) Review: Are animal models predictive for humans? Philosophy, Ethics, andHumanities in Medicine, 4(2).


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Why lack of predictive value? Why that manyfalse positive and false negative results?

1. Theory of complexity: small differences can

generate big effects Gene regulation, complex interactions

E.g. chimpanzees: 98% of genes in common withhumans, yet not susceptible for HIV, hepatitis and

malaria (false negative tests)2. Theory of evolution: small and large differences

between individuals, populations and species


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Current biomedical research (medicins and toxicsubstances): very specific, strongly dependent oncomplex interactions of genes,

At this specific level: differences between species(and populations, sexes, ages, individuals)become important

No longer at a rough (less specific) level (such ase.g. the overall functioning of blood vessels

Additional confounding factors: breedingprocedure, stress in animals, sickening (infecting)animals


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Alternatives of animal experiments become

more and more reliable, because more

human-specific and more technological

developments

Epidemiological research

Clinical research

Autopsies

Human (stem) cells and tissue cultures


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New technologies

Computer simulations and mathematical models

Microdosing

MRI-scanners


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New technologies

Gene chips (DNA microarrays)

Human-on-a-chip


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Animal testing can be harmful to people:

1. Misleading

False positive and negative results:

Preventing development of good products

Allowing harmful products

Alternatives are more reliable, so fewer false

positive and false negative results Animal studies are wasting scarce resources

(money, time)


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Why are there still animal experiments?

Psychological mechanisms of animal

researchers

Habit

Belief

Peer pressure

Money


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Step 1: what if animals were not sentient?

Science

Step 2: what if animals are sentient?

Ethic of well-being


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Step 2) ethically irresponsible: welfare

loss in animals

Animals are too different from humans forcontemporary biomedical research

But animals are equal to humans in terms ofglobal functions: circulatory, respiratory,

and consciousness (feelings)!

So: Concerning what is ethically relevant: strong similarity

between humans and animals

Concerning what is scientifically important: strongdifferences between humans and animals

According to animal researchers: the opposite!


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loss in animals

Well-being of animals should be taken intoaccount

Place yourself in the position of an animal used in

experiments, and measure the loss of well-being Increase well-being of everyone, giving priority to

the worst-off

Loss of well-being due to breeding, confining,testing and premature killing of animals

Lab animals are often in the worst-off positions


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loss in animals

Three Rs

Refine

Reduce

Replace

Credibility of animal researchers?

Regularly violating 3Rs in earlier experiments What do researchers eat?

No vegan: researchers violate 3Rs 3 times a day!

Animal products are not necessary for healthy diets


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Step 3) ethically irresponsible: animal

rights violations

Humans not only have a right to live and to flourish

Also the basic right not to be used as merely a means tosomeone elses ends

Humans are not tools E.g. slavery No use as property

No coerced human experimentation Not even according to 3Rs

Not even if well-being of other people would increasemore (if human experiments would be beneficial for a vastmajority)

Not even if seriously mentally disabled orphans would beused


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rights violations

Species is not morally relevant

1. Arbitrary: why species instead of population,

subspecies, genus, family, order, class,?

2. Artificial and far-fetsched: how to define a

species? Relevance of fertility of potential

offspring?


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rights violations

3. Fuzzy boundaries:human-animal hybrids,chimeras, ancestors,genetically modified

humans?

4. No merit: we did notchoose to be born ashumans

5. Comparison with racism:genes not morallyrelevant


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Conclusion

Step 1: many experiments should stop

Step 2: more experiments should be

prohibited (not only for cosmetics)

Step 3: nearly all animal experiments should

be prohibited

ethics of animal experiments in 3 steps by stijn bruers

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