Although researchers are committed to finding new ways to reduce and replace animal testing, current technology cannot yet replace many types of animal research. The Nuffield Council on Bioethics estimates that between 50 and 100 million animals, from flies to monkeys, are euthanized for research each year worldwide, with roughly 90% of the vertebrate animals used for research being rodents.
尽管研究者们一直在努力寻找减少和替代动物试验的新的方式，目前的技术依然无法替代许多种动物研究。Nuffield生物伦理理事会估计全世界每年有5千万到1亿只动物，从飞虫到猴子，因为研究而接受安乐死，其中大约90%用于研究的脊椎动物是啮齿类动物。