There is a strong utilitarian case for a pragmatic type of vegetarianism, based on the idea that eating meat usually causes suffering and that it is wrong to needlessly make something suffer. See this article (Singer, Utilitarianism and Vegetarianism, 1980) for a discussion.
The argument is based on a type of pragmatic consequentialism: we are interested in concrete decision making (should I eat meat or vegetables for dinner?) and choose among different possible actions based on their consequences.
What are good critiques of this moral justification of vegetarianism that stays in the framework of pragmatic consequentialism?
Some starting points: