Friday, 27 July 2007

Ethics of animal research

I think the view of the British public is that raising, killing, and eating animals for food and other animal products is perfectly normal, natural even, and nothing to be concerned about. On the other hand, animal research, or vivisection, is a rather distasteful furtive practice that is only tolerated because of the benefits it brings humanity - but must be constantly monitored and regulated to keep it in check.

They're only half right. Their concern for fluffy rabbits and cute monkeys doesn't seem to extend to battery hens or other food animals and this is a rank hypocrisy motivated entirely by a refusal to think about the issues coupled with an irrational sentimentalism. I'm with Peter Singer that animal welfare has to be part of a utilitarian ethic, and based on current farming practices eating meat and animal products fails that cost-benefit analysis.

So why am I in favour of animal research? The reason is pretty simple, on a cost-benefit calculation animal experiments can bring benefits to humans, organisms that weigh very heavily in my moral calculus, at the cost of animals, which weigh somewhat less (depending on species and experiment performed), and these benefits cannot be got through other methods. Contrast this with eating meat which is pretty much unnecessary for me in my rich Western environment, and where rearing and slaughtering methods are far from halcyon.

Most people would probably accept my analysis of the need for animal research, even if they reject my arguments for vegetarian/veganism. And this is the fundamental problem of the anti-vivisection movement, they can put forward a logically consistent, even respectable argument against animal research, often based on a position that essentially rejects privileging humans over other animals (although not necessarily), but most people will never accept their arguments.

So what are they to do? Fortunately for them, there is another line of attack. If the animal suffering end of the equation isn't powerful enough, how about questioning the benefit to humans? Now this isn't entirely an opportunistic strategy, many anti-vivisectionists have convinced themselves of the futility of animal research for benefiting human health because of the cognitive dissonance inherent in the (intellectually respectable) position that whilst animal research may benefit human health, these benefits are outweighed by the suffering of the animals.

Many anti-vivisectionists go further than just asserting that animal research is useless, they want to argue that it is actively harmful to people's health. An additional line of attack is to assert that we don't even need to do animal research, there are in fact a range of super-dooper alternatives that are being ignored by the pharmaceutical companies and evil scientists with their vested interests (these include 'computer models' and 'in vitro' tests, it is never entirely clear how these are supposed to be developed, and how exactly they are meant to work, but the anti-vivisectionists seem quite taken by these mythical beasts).

Now I've spent some time working on researching disease in humans, yet I have, on occasion, carried out animal research in pursuit of this, and constantly rely on the results of studies into animals when interpreting, planning, and evaluating my own work. In fact, if you ask doctors and medical researchers the vast majority will stress the value and relevance of animal studies. Without animal research I wouldn't even know where to begin studying the human brain - it would just be a big squidgy blob of tissue.

Now anti-vivisectionists are not entirely wrong that a whole lot of research goes on that is of, shall we say, questionable relevance to human health (and I've argued before that science could do with a little more direction, in terms of funding). And I can accept that perhaps the existing regulations are not as well enforced as they could be (although I do think the legislative framework is pretty good, and justifiably strict - if unnecessarily bureaucratic). But they go way beyond this. I have a familiarity with the pseudo-academic works of Shanks & LaFollette and Ray & Jean Greek, as well as the continuum from national campaigning to street level demagoguery of the BUAV, SPEAK, Animal Aid, X-CAPE and a host of others.

I feel like I should present some critique here of their overall position, but it is really impossible because they are generally so incoherent, scattergun, and ill-informed that they can only be countered on an argument by argument basis. Not that I would advise actually trying to engage any of the true believers as they are impressively inflexible in their thinking and quite unable to connect with a rational argument. However, there is a loose thread that runs through these arguments, and that is the view that animals are so different from humans that we simply can't infer anything about how humans work from looking at animals - now stop snickering at the back and muttering 'DNA' into your hand these people are serious - they draw a lot of their intellectual strength from Shanks & LaFollette and the Greeks, but the argument is essentially that because humans and animals are not exactly the same you can't extrapolate from one to the other. That is pretty much it, with a variety of anecdotes about how this or that drug works differently in humans than this or that species, oh, and mentioning thalidomide of course (yes, I know that thalidomide was never tested for teratogenicity in animals - but they apparently don't).

To get an idea of the level of argument we're talking about here's an exerpt from a BUAV 'report' on animal research in Parkinson's disease, and compare their claims with the development of deep brain stimulation for Parkinson's disease using animal models:

"From a scientific point of view, animal 'models' of PD should be stable over a long period of time so that the effects of new therapies can be evaluated. However, the fact is that the signs and symptoms in primates vary over time, even between individuals. Additionally, specific signs of illness in individual animals used as indicators of the severity of their condition contradict each other, making data interpretation more difficult. There are serious underlying limitations to the primate 'models' of PD which include:

  • Symptoms are caused by toxin injection and appear rapidly in primate 'models'. The causes of human PD are unknown and symptoms are
    slow to develop.
  • Because of the artificial causation of the condition in monkeys, little can be learned of the causes and progression of the human disease.
  • Compensatory mechanisms in surviving brain regions are likely to be different in lesioned monkeys compared to PD patients.
  • If dosing is stopped, neurotoxin-treated primates show partial but variable recovery (and there is variation between old and new world monkeys). However, humans always show a progressive worsening of the symptoms over time.
  • PD usually affects older people with comorbidities, while the monkeys used in research are young and otherwise healthy.
  • In the affected brain regions of primates, Lewy bodies are either never seen or only very infrequently. Yet in patients, these cellular inclusions are the classic hallmark of PD.
  • MPTP-treated primates show limb tremor only sporadically. In PD patients tremor is marked and sustained. The cognitive patterns of impairment also differ between primates and patients.
  • In neurotoxin-treated monkeys, specific dopamine-containing brain cells are damaged in one part of the brain. In PD, damage is more widespread and involves other neurotransmitters, in addition to dopamine.

Replacing primates in fundamental PD research
Functional imaging has a key role to play in human studies of Parkinson's disease, thereby avoiding problems of species differences and artificiality of the model. Positron emission tomography (PET) imaging has been used to measure levels of dopaminergic activity in the brains of Parkinson's patients. This sheds light on the pathophysiology of the condition, and permits direct study of disease progression at a biochemical level. PET imaging has revealed disturbances of brain functional interactions and cognitive information..."

If you're familiar at all with neuroscientific research, and Parkinson's research in particular you'll be able to see what crap the BUAV are talking moaning about fairly peripheral issues to do with disease progression, whereas the scientists went into the the brains and found a bit that lesioning or stimulating could actually control the symptoms and then translated that into human patients (take a look here at what it can do for real live human patients). No matter how many PET studies you perform you really can't find this kind of stuff out without getting inside that brain - you are not going to look at a PET scan, say 'oh, that bit looks like it lights up a lot in PD, let's cut it out of some people and see if they get better'.

Of course these animal models are not exatly the same as the human disease, but they're not trying to exactly reproduce the disease, they are simply trying to reproduce the relevant problem (dopamine depletion) and find relevant solutions (deep brain stimulation). I could go on about how the normal physiology of the brain can only be discovered by research in animals, and about how much we've learned from animal studies that we've been able to use to interpret the pathology in human disease, but examples of successful research like this are better than any argument I can produce to show how unfounded this sort of stuff from the BUAV and friends really is.

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