Apples and oranges. Most of these aborted fetus' are aborted before they're anything that closely resembles a functioning human. They are not given the chance to live a highly probable abusive/neglectful life by parents who don't want them or in foster care, etc. IMHO abortion (not late term--that's disgusting unless necessary to save the mothers life) is a logical and humane option to people forcing a child to life through what is, in very high probability, going to be a potentially miserable life by removing that possibility before the fetus has developed into something that can think or feel like a human.
Animals are treated horribly poorly, even the most intelligent ones. Why? Because they simply lack the ability to verbally communicate us and tell us "please don't". Taking advantage of the living weak and treating them like absolute shiit is much more dispicable to me than stopping germ cells from developing into a creature that can be destroyed by the negativity it was brought into in this world.