You are trying to justify one strand of unethical behaviour (how humans have bred dogs) with another. Not sure that holds up.

Can you unpack why you think breeding dogs - by which I take you to mean all dog breeding, not just the kind that leads to serious physiological issues such as breathing difficulties in pugs - is unethical?

>how humans have bred dogs [was unethical]

This is far from being a consensus, I think.

I'm not sure if I see this line of reasoning. Nature has countless symbionts, parasites etc, are those all unethical?

My ethical framework agrees with you, but ethics, like everything, are relative.