I recently disocvered www.jove.com – that is the Journal for Visualised Experiments. On this website you can see how animal (and non-animal) experiments are carried out with the utmost care and scientific precision. Everything from mice running mazes to invasive neurosurgery are carefully filmed and explained to show correct procedure. From various videos we can see the care is made to ensure animals to do not suffer unnecessarily, and that steps are made to reduce any pain that might be caused – usually down to zero.
Although some experiments may look unpleasent, it would be no different that seeing yourself under the knife during a hospital operation – an event which is painless for most people (due to anaesthetics – a type of drug developed using animal research).