Full Idea
It was precisely the inability of utilitarianism to explain the distinction between animals and people which led to its rejection.
Gist of Idea
Utilitarianism is wrong precisely because it can't distinguish animals from people
Source
Roger Scruton (Animal Rights and Wrongs [1996], p.50)
Book Reference
Scruton,Roger: 'Animal Rights and Wrongs' [Demos 1996], p.50
A Reaction
A nice turning of the tables, rejecting the utilitarian pride in incorporating animals into their theory where others (like Kant) reject them. Yet in one respect (suffering) they are inescapably very like us.