So why don't we feel the same compassion about the pain of chimps? Or Gorillas? Why isn't the killing of them deemed murder? It should be - if you're going to make laws around the 'personhood' of a fetus, capacity to suffer being the deciding factor.
Murder is a distinctly human crime. But I think most people are against the needless killing and avoidable suffering of animals. Sadly, not enough pay attention to cruel factory farming methods or the products they buy (such as those containing palm oil)