Deleted because this is done & over with. Thank you Ludi for your kind response.

It's a matter of different value systems, and it's very difficult to argue values. Maybe some of the philosophers/ethicists here could do it. People who are in favor of animal testing for medical reasons believe that humans are absolutely more important than animals. And I don't think there is any way to argue them from that position. It is a very deepseated part of our culture. The only effective argument you might be able to make might be that animal experiments don't help with human medical knowledge, and I just don't know if you can support that argument with enough evidence to convince this person.