Dogs actually protest much less at such treatment than pigs. I can't remember who the author was, but I remember reading a report that a scientific institution had given up doing vivisection experiments on pigs because thy made too much fuss and went back to dogs, which accepted their lot quite calmly and placidly even whilst the scientists were cutting them open on the table. The thing is, pig hearts are actually very similar to human hearts; so if human test subjects aren't available it makes sense to a certain extent to use pigs; I like it no more than you do however.