Is it really feasible to stop using animals for basic medical research in view of the need to observe the complex interactions of cells, tissues and organs?
Besides the moral issues involved, clinical and epidemiological studies of humans offer a far more accurate picture without hurting anyone. Observing interactions in animals is no guarantee that the information can be extrapolated to humans. Different species of animals vary enormously in their reactions to toxins and diseases and in their metabolism of drugs. For example, a dose of aspirin that is therapeutic in humans is poisonous to cats and has no effect on fever in horses; benzene causes leukaemia in humans but not in mice; insulin produces birth defects in animals but not in humans and so on. Animal experiments cannot replace careful clinical observation of human beings.
