The Lankavatara Sutra has expounded the many faults of eating meat. We will only discuss the three major ones here. The first is that all sentient beings have been parents to one another since beginningless time. As such, the animals that we eat today surely have once been our parents too. Eating these meat will be like eating the flesh of our own parents or children. It is therefore a wrong thing to do even from the mundane perspective, let alone the supramundane point of view.
[Excerpt from Luminous Wisdom Book Series 1: The Right View ~Why Vegetarian?]