Richard Adams said this quote

I dislike this whole business of experimentation on animals, unless there's some very good and altogether exceptional reason to this very case. The thing that gets me is that it's not possible for the animals to understand why they are being called upon to suffer. They don't suffer for their own good or benefit at all, and I often wonder how far it's for anyone's. They're given no choice, and there is no central authority responsible for deciding whether what's done is morally justifiable. These experiment animals are just sentient objects; they're useful because they are able to react; sometimes precisely because they're able to feel fear and pain. And they're used as if they were electric light bulbs or boots. What it comes to is that whereas there used to be human and animal slaves, now there are just animal slaves. They have no legal rights or choices in the matter.