HT: You cannot, in my opinion, be pro using animals in experiments for SOME things, but anti them for others. I used Maurice's analogy to his religion, since in a past discussion he said you can't pick the bits out of Catholicism that you liked, and discard the ones you don't. You're either a fully-practising Catholic, or you aren't a Catholic.
In the same way, you are either in agreement with the use of animals for experiments, or you are not. You can't pick out the bits you like, and discard the ones you don't. (Of course, I suppose there's the 'undecided' sector, like there are agnostics, and demi-vegetarians, but I wasn't talking about fence-sitters in this context.)
I'm not sure I can put it more simply than that.
As for the 'morals' of the issue, I think that goes well beyond simplistic notions of 'right' and 'wrong'. If I believe there is a God, and that God gave mankind dominion over all the earth and the animals thereon, then I won't have a religious dilemma about utilizing God's gifts in the way I think fit. We (as mankind) farm them, eat them and their dairy products, use them for pulling carts and ploughs, for their hides and horns, experimentation, and for sporting purposes. I don't know any part of the Bible, Torah, or Koran which proscribes the use of animals by humans (apart from pork and shellfish for Jews and pork for Muslims), and believers could well argue that, while it mightn't have been foreseen some two millennia ago, the right to utilize creatures in any way was given the okay by the Almighty.
If I don't believe in God, and don't have a religious compass, it comes down to issues of personal choice and belief. Well, those, and what one's government allows.
If I believe there is nothing wrong with using animals for meat, labour, or sport, why would I draw the line at them being used in ways which should enhance the health of mankind?
If I believe it's inherently wrong to exploit animals in any way, I'm a dead cert to abhor their use in experimentation and the development of medicines, the farming of their organs, or the use of their skin for burns sufferers, etc., etc.
Thousands of people look at the labels of toiletries, household products, clothing, etc., to ensure that no animal by-products are contained in their manufacture, and accordingly have a perfect right not to use pharmaceuticals which have been made on the foundation of animal experimentation. There are plenty of websites available (and good old-fashioned books) to steer those so minded away from such manufacturers, and onto 'animal-free' ones. Likewise, such people also have the right to refuse treatments which would include the use of animal products such as skin or transplanted parts. It's their call.
What I wouldn't understand was someone proclaiming their rare steak to be delicious, and then saying it was 'cruel' to breed guinea pigs for lab work. From a purely personal point of view, I'd have to say that I couldn't see one form of use from the other, since the end result is dead animals. (Although I believe some chimps and orang-utans are FINALLY donated to zoos for rehabilitation, if someone cavils.)
I eat animal products, I use leather, and I enjoy animals both as sporting creatures and have enjoyed them very much as companions. I cannot turn round and put on a moralizing stance about their use in labs, then. I would only hope that whatever work is done is actually ESSENTIAL, of clear-cut benefit, takes as little time as possible, that the animal is treated well, and that if at all possible does not have to die. Unfortunately, just like the dodginess that is the pet trade, I'm unlikely to ever know, since the more threatened labs are, the more they're likely to be heavily guarded and kept secret.