The primary non-rodent species used in toxicology is the dog. It is generally agreed that, for ethical reasons, dog use should be reduced to the minimum consistent with maintaining the scientific quality of toxicology studies and ensuring human safety. Dog use in toxicology has been discussed widely, both from a scientific and ethical viewpoint, and there appears to be real potential for achieving significant reductions in the number of dogs used in pharmaceutical safety testing. An industry animal welfare initiative commenced in 2000, with the aim of evaluating and, where possible, putting into practice, scientifically valid approaches to minimise dog use in regulatory toxicology without increasing the use of other non-rodent species, such as non-human primates or minipigs. The study's Steering Group categorised potential reduction approaches into three distinct areas, one of which is the production of a best practice guide on aspects of study design, including: group sizes, use of control animals, single sex studies and design of maximum tolerated dose (MTD) studies. Information on current practice and experience within the pharmaceutical industry is now being analysed, and additional input is invited.