Animal testing is a necessary evil - Zari's blog



Is animal testing a necessary evil?

Animal testing is often presented as the only way forward for medical research. Despite the many ethical issues raised by subjecting animals to confinement, isolation, pain and eventual death in laboratories, it is a common supposition that we are overlooking moral qualms in the interest of saving lives. However there is a very strong pragmatic case for abandoning the use of animals in medical research, as it is this practice that has led to numerous health disasters, as well as setting back valuable research through a vast proportion of misleading inferences.

The biggest problem with vivisection as a means of research into human conditions, is the disparity between the molecular make-up of different species. It is claimed that other animals are similar enough to humans to provide useful results when testing the effects of various drugs. However, that certain parallels that can be drawn between humans and related mammals is not basis enough to form valid conclusions about responses to drugs which may be unique to humans, indeed animals that may seem very similar often have completely converse reactions to chemicals and treatments. This is clearly demonstrated by the testing of suspected carcinogens on rats and mice by the American National Institute of Environmental Health Sciences, where less than 70% of the responses in the two species showed a correlation. If there is this kind of inconsistency between such closely related species, how can we hope to apply the observations from animal tests to humans? There is no way of predicting where two species will react similarly to a substance, and where its effects will differ. Instances of drugs that have been successfully developed through animal testing are not enough to justify the risks taken each time a chemical is supposed safe for humans by analogy with similar species.

Not only do the useful and harmful properties of drugs vary between humans and other animals, but experimentally triggered illnesses may be significantly different to those that occur naturally. In the case of ischemic strokes, animal research discovered 25 compounds that would reduce damage in rodents, cats and other animals, none of which had any effect when tested on humans; this was put down to the discrepancies between a stroke occurring spontaneously and one that has been induced in the laboratory. The stress suffered by test subjects, in terms of handling, living conditions, and the processes they are made to undergo, may also distort results. The trauma and anxiety animals suffer throughout the research procedure can lead to a weakened immune system, as well as hormonal changes that can alter the way their bodies react to a condition or treatment. Moreover, introducing human ailments into other animals is not always straightforward, highlighting the subtle biological differences between species as well as posing a practical problem for researchers. Over a 10-year period, of approximately 100 chimps infected with the HIV virus, only 2 became sick. Additionally, chimps don’t show the antibody or cell-mediated response to the virus that humans do, making their inclusion in research of vaccine development futile.

The lack of reliability of results obtained through animal experiments renders the practice counter-productive, leading to potentially dangerous drugs being passed as safe, and hindering the development of genuinely beneficial medicines. Research into the polio virus was set back by 25 years due to the subscription of doctors to the model of polio in monkeys, our closest evolutionary relation. Despite human studies having demonstrated that the gastrointestinal system was the route of infection for this virus, the incongruous observations from experiments using monkeys delayed the development of a vaccine, costing innumerable lives. The arthritis drug Opren was found to be safe in monkeys, but killed 61 people before being withdrawn from the market. We cannot trust that substances presumed safe through animal testing actually pose no harms to human users; conversely, many drugs that cause problems in animals may have no adverse effects on us. Aspirin, one of the most useful medicines widely available today, causes birth defects in rats, mice, guinea pigs, cats, dogs and even monkeys.

Wrongly, there is a perception that animal testing is still necessary due to a lack of viable alternatives. In fact, we have far more trustworthy means of gaining information into human ailments and their potential cures. Human cells obtained from biopsies, post-mortems, surgery waste, or the thousands of placentas discarded every year, can be cultivated and used in the laboratory. Such cell and tissue cultures already produce vaccines, test for toxicity and develop significant drugs to aid a number of conditions. The use of human cells solves the problem of relating one species to another, thereby providing a far superior method of investigation to inefficient animal experiments. Technology also now makes it possible for further analysis on a molecular level, facilitating the identification of genes that predispose individuals to certain conditions using DNA samples from human patients, and removing the need to model illnesses in genetically modified animals. Research into malaria and cancer treatments is currently being aided by equipment that allows for the study of a drug’s molecular interaction with human DNA.

One of the contentions of vivisection supporters is that while such alternatives can be used in conjunction with animal tests, there is a continuing need for research using entire organisms. Investigations using cells and various human tissues cannot provide doctors with a full image of a chemical’s consequences on a human body, and problems such as birth defects cannot be identified unless trials are carried out using pregnant animals. However, as shown by the Thalidomide incident – a drug that causes birth defects only in humans and rabbits- this disastrous side-effect is no less subject to inconsistencies between species than any other, again making animal tests irrelevant. While there is no ideal solution to this problem, the continued use of animal testing merely serves to impede medical progress due to the wide discrepancies between results. Computer models of whole biological systems are now being developed, and can be used to predict the actions of new drugs; such models of the placenta and foetus allow for the study of unborn babies and can provide insight into problems affecting unborn babies.

A fundamental tool in the development of new treatments is research directly involving humans. Epidemiological research has successfully led to an understanding of many prevalent medical problems such as heart disease and various cancers, and allowed doctors to identify the risk factors involved in developing such conditions. It has also been key in determining the possible genetic, environmental and medical causes of birth defects. Furthermore, it is becoming increasingly feasible to study individual human volunteers, through non-invasive scanning and imaging procedures, and this is already proving useful in the investigation of epilepsy. Functional Magnetic Resonance Imaging is a technique for determining which parts of the brain are activated by different types of physical sensation or activity, and is assisting research into pain, stroke, and neurological diseases such as Alzheimer’s.

The ethical objections raised by the use of animals in medical research need not, and should not be disregarded. Animal subjects are genetically modified, infected, mutilated, injected with various chemicals, and there is very little that can be done to regulate the harm and suffering they experience when the very nature of the experimental process is to mimic the harm caused to humans by various diseases and disorders. There is an automatic moral response in most to condemn animal testing on grounds of inhumanity, and it is due to the misguided view that vivisection is productive and necessary that this knee-jerk moral reaction is overlooked. That animal testing is a productive, reliable means of developing drugs is a mere assertion, and instances of medical disasters caused directly by the misleading results it provides show how risky and inaccurate it really is. Even when discounting the ethical implications of this research method, the practical problems and dangers it poses give reason alone for its discontinuance, and the availability of other more consistent and applicable investigative techniques mean there is no imperative for further use of such an imprecise, fallacious practice. If we concede that animal testing is indeed an “evil” in terms of the moral dilemma it presents, this merely serves to make its inevitable downfall even more essential.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download