Last year, Angela Walder applied her own version of the cost-benefit analysis to a 1987 case from John Radcliffe Hospital, Oxford, where 42 dogs died. As part of a study into the "immunosuppressive action of Cyclosporine A" (a drug used to stop human rejection of transplanted organs), 18 dogs had parts of their intestines grafted to those of other dogs. "We question why such mental and physical suffering was inflicted on an excessively large number of dogs," says Walder. "We believe these experiments should not have been approved."