Animals (Scientific Procedures) Act 1986 experiments licensed under the 1986 Act. The 1986 Act defined "regulated procedures" as animal experiments that could potentially cause "pain, suffering, distress or lasting harm", to "protected animals", which encompassed all living vertebrates other than humans, under the responsibility of humans. A 1993 amendment added a single invertebrate species, the common octopus ("Octopus vulgaris"), as a protected animal. The Act applied only to protected animals from halfway through their gestation or incubation periods (for mammals, birds and reptiles) or from when they became capable of independent feeding (for fish, amphibians and, the common octopuses). Primates, cats, dogs and horses had
Animals (Scientific Procedures) Act 1986 inquiry compared the Act to legislation from France, the U.S., and Japan. The report concluded that "virtually all witnesses agreed that the UK has the tightest system of regulation in the world" and that it is "the only country to require an explicit cost/benefit assessment of every application to conduct animal research." Note that costs are explicitly in terms of adverse effects on animals, not the financial cost to the experimenters. In 2005, Patricia Hewitt, then British Secretary of State for Trade and Industry, called the Act "[among] the strongest laws in the world to protect animals which are being