Schrödinger's Kitten

Irreverent Science for Everyone

Wednesday 02 September 2009

Testing Animal Testing

  • policy
  • animals
  • measurement

Pretty much everyone agrees that animal testing should be less cruel and, if possible, avoided. But this simple proposition opens a whole can of worms (...and daphnia, and drosophilia, and other quickly-reproducing invertebrates...). How do we minimise animals' suffering when we have no idea when they are suffering? Humans aren't great at taking animals on their own terms; witness all those dog owners who think their canine friend hatches vindictive plots to punish them for going out without them. For years it was thought that reptiles were crap at learning, but once they were offered rewards that actually appealed to them (heat lamps rather than food rewards) they suddenly improved. Some animal researchers don't even believe that animals *are* conscious. And then there's the issue of interspecies comparisons — is it better to test on 1,000 zebrafish, or one cat?

No wonder that animal testing legislation is a patchwork of make-do and subjective assessments. But that's no excuse for it either.

A quick glance round society will tell you that not all organisms are created equal, nor are they treated equally. Even the most militant vegan will devour carrots and treat yeast infections (for the purposes of this article I will be ignoring the fruitarian diet, which, as it sounds, doesn't allow for the killing of a whole plant, just the removal and devouring of its developed sex organs). Many self-identified 'vegetarians' eat fish, and noone but Jains worry about treading on ants. Clearly being a living organism isn't enough to grant you an ethics board.

Attempts to reduce the use of animal testing are usually based on 'the three Rs' — replacement, reduction and refinement. Reduction refers to the process of using fewer animals for studies, refinement to ways that the animal can be less distressed by the process, and replacement by using non-animal alternatives or "a 'lower' life form where possible". I assume from reading this that a 'lower life form' is one less capable of suffering. But how can the suffering of a rat be compared to that of a zebrafish? A behavioural comparison would be fairly tricky, since zebrafish refuse to fill in personal information on surveys. Often, 'lower' is taken to mean phylogenetically lower, which leads to some interesting situations. The common octopus exhibits such sophisticated behaviour that it has been upgraded to an 'honorary vertebrate' in testing legislation, getting perks including mandatory anaesthesia before surgery. However, what you can do to its closest relatives, let alone other cephalopods, is limited only by your imagination — despite the fact that they're hanging from the same branch on the evolutionary tree.

Assessments of the level of stress, and distress, individual test subjects are under is equally fuzzy. As the UK's Animal Testing Licence training document rather coolly puts it: "considerable differences of opinion frequently arise when several people assess the same animals." A scientific experiment where the effects of the methods used are a matter of opinion raises some questions, which are exacerbated by the significant differences in assessment. Some researchers, observing that injured fish will 'baby' an injury, and withdraw from normal behaviour while hurt, only returning to normal when medicated with painkillers, have concluded this is evidence fish are capable of suffering. Certainly, that's what people concluded when mammals performed the analogous actions. However, fish do not even merit consideration under animal testing legislation in the US, presumable being classed instead as some sort of highly mobile vegetable.

In order to reduce animal suffering, the test species should be the one who will suffer the least but still produce relevant results. Researchers already evaluate the suitability of different species for their studies — what is missing is a reliable objective measurement of the distress each would experience. Many scientists have an aversion to talking about mental states as part of science, since they are essentially subjective (unlike animal testing legislation or observations of quantum phenomena). But animal researchers and psychologists already attempt this daily — is it so big a stretch to slap a ranking on it? Neuroscience is already taking baby steps towards this, using techniques such as functional MRI scans to link subjective mental states to patterns of neuron activation. Electroencephalograms have also been used to assess levels of consciousness, although no firm boundaries have yet been drawn.

In a less ambitious departure from current procedures, researchers have also used automated techniques to record behavioural changes. Infra-red monitoring can record changes in movement level and indicate sheltering behaviour, while in the News of the Blindingly Obvious Dept., audio recordings of the squealing of piglets reveal that they find castration painful. Nevertheless, automating such simple observations has a big pay-off. Not only does it reduce drudgery, it could eliminate the biasing effects of our typically closer relationship with traditional pet animals, to the detriment of others with less active PR departments.

Trixie, a cute rat

(Photo courtesy of Peter, PKMousie)

Not to mention overcoming the 'protect small things with big eyes' bias evolution has saddled us with. However, these methods wouldn't help much with inter-species comparisons, so an approach based on neural activity would be preferable.

Such a standard could be applied across a variety of species, and would be free of anthropomorphic bias and personal sentiment. Of course, given the elusive nature of consciousness and the rapidity of change in the fields of neuroscience and neuropsychology, any attempt at an objective measure of suffering will be constantly subject to revision — but just because something is difficult to detect is no reason not to try and detect it (hello, dark matter researchers!).

Content: Scary Boots — Design: Canis Lupus