A working party, comprising two animal welfare organisations and some 12 pharmaceutical companies in Europe, was established to minimise the use of the dog in safety testing. As first step, the participants defined the major objectives of preliminary dose-range finding/MTD toxicity studies in non-rodents, defined the principles and requirements for this study type and agreed on a proposal for an optimised study design, based on collective experience of conducting such studies in industry, involving an evaluation of 100 individual study data sets. The suggested study design is explained and described, and reflects current best practice in the pharmaceutical industry in Europe. The implementation of such an optimised design is believed to result in a reduction in the overall numbers of animals used for this purpose, without jeopardising the scientific rationale and usefulness of the studies for informing the conduct of later regulatory studies.