Animal testing allows scientists to test and create new drugs. Animals such as monkeys or rabbits have similar physical processes to humans. This allows scientists to test the effects of certain drugs. If a drug produces adverse effects in animals it is probably unfit for human use.
Animal testing is cheap. There is a large supply of animals for medical research. Animals are easily bred, and maintained safely in controlled labs. The costs of testing in humans would be extremely high.
Many people argue that animal testing is cruel. In some cases this is true. However it would be much crueler to test new drugs on people or children, or to let people die because there was not enough information about a drug. Furthermore, legislation in most countries sets standards for animal treatment, and laboratories have guidelines to prevent cruelty.
Animal rights campaigners claim that we don't need new tests because we already have vast amounts of information. However, many new deadly infections appear every year and new treatments and drugs are needed to combat these deadly plagues. Animal testing is needed in the world we live in. Our responsibility is to manage the animals in our care and balance their suffering against the good that comes from