I definitely believe that the fact that animals may be turned over to research should be in 20+ point font on the top of the sign-over page, and well as posted at the entrance to the shelter when people bring the animals in. I also think that there should be some sort of protection for lost animals, ie, only allow owner give-ups to be funneled to research. But, animal research is necessary.
We are trying to move away from it, and we always try to respect and minimize the animals used in our lab, but we do have to use animals. In silico and in vitro methods are getting better and better, but we aren't there yet. Here's an example: I abandoned part of my project because I couldn't find a way to make an antibody for my protein (either monoclonal or polyclonal) that did not involve killing animals. I couldn't do it myself, but this just means that the next person who works on my project will have to do it.
I can't speak much about the animal research done in my lab, because I have a fatal allergy to rats and mice, therefore cannot go into the animal facility, but I do hear the reports at group meeting, and see the care taken on infection and sacrifice days.
Sometimes purpose-bred dogs and cats are not the best fit for the research being done. For example, sometimes, retrovirus researchers need naturally infected FIV+ cats rather than laboratory infected cats, and an animal shelter is the best place to find these cats. Sometimes the purpose bred animals are too inbred, or too unsocialized.
It is sad, and I hate that it has to happen, but, I think making a small contribution before dying, is preferable to just dying.
-Nicole