Argument: Animal responses to tests can be different than human responses
Marymoose. "The Case Against Animal Testing". Helium - "One of the main arguments against the use of animals in research is that animal studies can't actually confirm or refute hypotheses about human physiology or pathology. In straightforward terms, it can be argued that only research done with humans is relevant to humans."
"Animal Experiments". BBC.co.uk. Updated August 17th, 2004 - "Animal experiments can be misleading. An animal's response to a drug can be different to a human's"