I disagree as you are stating it. I had already made clear I am against any kind of abuse, I am of course not talking about bestiality as in raping a coat.
However, I think you are underestimating animals, they are often able to express consent or rejection.
If a dog gets excited by frotting my legs, and I get aroused by it, would it be abuse if I help him to cum and I bust it in the process? Just one example.