Animal models are believed to be predictive for drug development in human health care. While LD50 studies of drug candidates have always been performed in animals like rodents or dogs, efficacy and adverse effect studies using animals as a model for humans were prompted only in the late 1950s, as a consequence of the thalidomide scandal, where thousands of babies were born with severe extremity deformations.

In the last 10–15 years, preclinical research methodologies have increased crucially regarding measurement of sensitivity and specificity. Adapted and improved for dedicated use in animal research, positron emission tomography (PET) and single photon emission computed tomography (SPECT) are good examples of such methodologies. It seems to us that increased measurement precision in animal research has somewhat raised expectations regarding human outcome prediction of preclinical data. In recent years, on the other hand, there has been increasing scepticism about the essentiality of animal models for medical progress [1–7]. Statements like “virtually every achievement of the last century has depended directly or indirectly on the research with animals” are often found in the literature to emphasize the importance and necessity of