Probably the most persuasive argument presented by groups opposing animal use in research is of pain and suffering being inflicted on these subjects. Most of the moral/ethical issues are rooted in the following scenario: a) if animals are assumed to react similarly to man to stimuli and drugs; b) and data collected from animal experiments is used to predict how stimuli or drugs will act in humans; c) then animals must possess man’s ability for feeling pain and for suffering. If this is true, it follows that scientists have a moral obligation to recognize and reduce or remove this suffering.
Recognizing pain or suffering can be difficult, as many animals mask their reactions when facing what they perceive as predators. The Guide states, “In general, unless the contrary is known or established it should be assumed that procedures that cause pain in humans also cause pain in animals.”
Some excellent web sites exist on this topic. A few of them are listed below: