Meh, pain is just an indicator. Of course animals feel pain.
For some reason people automatically associate that with how we as humans experience pain and learn from it.
It's not because my car is showing a "check engine" light, that's it's suddenly screaming in agony. It's just signaling to the "brain" something is wrong. How the approach then continues is clearly different between many species and this is what researchers are trying to learn.
Saying animals feel pain is obvious, speaking of "abuse" less so when you stop comparing the "experience" of pain to how we feel it.