Medical research on animals: facts and fiction

Most people are opposed to animal testing for products like cosmetics and household cleaners, but what about for medical research? With so many exaggerated claims surrounding the validity and necessity of animal experiments, it can be hard to know what to believe. So here FOUR PAWS separates fact from fiction.

Fiction: Animals don’t really suffer in experiments.

Fact: Around 115 million animals are used globally in laboratory experiments, including mice, rabbits, cats, dogs and non-human primates. Some of that research will be safety (toxicity) testing for industrial or agro-chemicals, consumer products and pharmaceuticals, or for basic ‘curiosity’ driven research. Around one-third of animal experiments in the European Union are for applied medical and disease research. All experiments have the potential to cause physical pain and mental distress to the animals. Medical research can involve highly invasive procedures during which animals can be infected with debilitating disease, given painful tumours, genetically modified to produce physical deformity, inflicted with wounds or broken limbs, subjected to surgical brain damage or given organ failure. Experiments can last for weeks, months or even years, during which time these animals can endure not just physical pain, but also psychological distress from their confinement and repeated subjection to procedures. Their capacity to suffer is no different from that of our animal companions at home, so when considering the morality of medical experiments on animals, it’s important to remember that for those creatures involved, life in the laboratory can be a considerable ordeal.

Fiction: Animals are similar to people, so using them makes sense

Fact: In medical research animals are used as ‘models’ for human disease by artificially inducing selected symptoms intended to resemble human illnesses. However, a disease is more than simply a collection of symptoms, and so the human disease itself and its underlying biology can never be fully replicated in an animal model. Furthermore, because there can be significant differences between people and other animals in terms of anatomy, physiology, metabolism, genetics and pharmacology, the illness can progress in remarkably different ways with often very different outcomes. Even a relatively minor molecular dissimilarity can cause significant variations in results, making extrapolating from animal studies to human patients highly dubious. So results from a study in mice can contradict results from a study in dogs which in turn differ again from people. Even mice and rats – two rodent species – can produce different results from each other, and different genders and strains of the same species can respond in dissimilar ways too. With this level of inter-species uncertainty, it can never be assumed that results from medical research on animals will be reliable or even relevant for human patients.

Fiction: Non-human primates are genetically close to humans, so their use is more justified.

Fact: Experiments on non-human primates are often justified on the basis of how genetically similar we are, but this overlooks the fact that often it only takes a relatively small genetic dissimilarity to produce a very big difference in the way we respond to diseases and potential cures. For example, chimpanzees have been used in AIDS research for decades but such research has spectacularly failed to produce a single AIDS vaccine that actually works effectively in humans. Macaques and marmosets are routinely used to research brain disorders such as Alzheimer’s and Parkinson’s disease, despite the fact that there are important discrepancies in the way these primates and human patients progress such diseases. So whilst treatments have been produced that alleviate the symptoms artificially created in laboratory primates, more often than not these have failed to result in effective and marketable treatments for people.

Fiction: If animal experiments didn’t work, scientists wouldn’t use them.

Fact: Animal experiments are often perpetuated for practical and historical reasons rather than because of their efficacy. Animals have been used for so many years - dating back in history to when our own medical knowledge was relatively basic and alternative techniques were almost non-existent - that they have become the default ‘gold standard’ despite a lack of credible scientific evidence to support this. Many scientists who conduct disease research without using unreliable animal models, say that obtaining funding for non-animal work can be far harder than if using traditional animal routes because it involves new techniques that challenge the status quo. High-impact journals can also resist publishing work that doesn’t involve animal studies. With research funding at a premium and grants often based on the number of papers published, it can be easy to see how scientists find themselves steered into animal-based research.

Fiction: Animal experiments are essential for medical progress.

Fact: Independent scientific reviews of animal studies indicate that animal experiments rarely translate into successful human trials. In fact animal studies can fail to predict human outcomes as often as 50 – 99.7% of the time. Therefore far from being essential for medical progress, it would appear that animal experiments come with a substantial level of uncertainty that can actually confound medical progress. The danger of relying on animal studies as the ‘gold standard’ is that false positive or negative results can have disastrous outcomes such as unexpected side-effects in human patients or potentially effective treatments being overlooked because they appeared unpromising in animals. In fact the US Food & Drug Administration says that 92% of pharmaceuticals that have successfully passed animal tests go on to fail in human trials. Poorly performing animal studies can waste vast amounts of valuable time and money that could be better spent on research that is more relevant to the human species.

Fiction: Animal experiments must continue because there aren’t alternatives.

Fact: There is already a huge range of non-animal techniques available that offer far more human-relevant approaches to medical research. If the money currently spent on failing animal studies were diverted to fund the development of even more non-animal technologies, future medical research could be based on cutting-edge, advanced scientific research tools capable of producing more reliable results at a faster rate. The quality and quantity of medical discoveries could be improved and the rate of drug candidate failures radically reduced. In vitro (test tube) and cell culture techniques to produce disease models based on human cells and tissue; computer modeling with three-dimensional virtual human organs and body systems to investigate potential new treatments; epidemiology (population) and patient studies including non-invasive brain research using sophisticated brain imaging techniques; ultrasensitive microdosing to provide vital human metabolism data in early phase drug development – these techniques and more could and should replace out-dated animal experiments.

How can I help?
Join FOUR PAWS and support non-animal medical research. We campaign peacefully and effectively for the replacement of animal experiments with advanced, non-animal techniques for the benefit of humans and animals alike.

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