To express disbelief in the concept of animal rights nowadays provokes shock, but such a response is intellectually significant:
The notion of rights seems often to crowd out all other moral considerations. It as if [sic] those who believed in animal rights could conceive of no other reason why animals should be treated decently or humanely than that they were endowed with rights. Without such rights, supposedly, any treatment of them would be permitted. In other words, the concept of rights in this case, as in many others, is a defense against an inner moral vacuum.
He nailed this one. I deal with this daily. I shoe horses and care for animals on various ranches and properties. So many of these people view their animals as people or extensions of themselves. Animals are animals. A dog is a dog and a horse is a horse, of course. To treat it other than such is disrespectful just as to treat a woman or a man other than who they are. This is why the claim of the civil rights movement had some strength. A Black man was a human and was to be respected as such not merely a diminished version of a white male.
Furthermore, animals think largely in alpha beta mode. They seek leadership or they set it themselves, there are no real in betweens. To have an animal live in an environment where it is an equal is foreign to it and causes it stress. Again, I see this daily. Such treatment is akin to having a human eat from a dog bowl, it would be disturbing to most humans.
Great point made in the comment section about how rights are not bestowed by the government for if such were true without government there would be no rights. I say, however, this is the case with animals, we bestow the rights and without us there are no animal rights as animals cannot claim their rights for themselves.