This is an important question, and it’s a hard one to answer. I don’t do any animal testing, nor does anyone I know, so I don’t know that much about it. I do think some animal testing is unnecessary, like testing for makeup or cosmetics.
However, modern medicine wouldn’t exist if it wasn’t for experiments involving animals. (This is true for both human and animal medicines.) I know there are a lot of rules and regulations that have to be followed before anyone can do any testing, and before a scientist can start tests they have to get the approval of a special committee and show that the tests aren’t unnecessary and won’t cause any excess harm or distress to the animal.
Beyond that, I can’t really give you any more information on animal testing, it’s not something I’ve read up on in detail. I’m very glad it’s not something I have to do as part of my research because it’s a very hard issue to deal with.