While some Tibetans to eat meat, the preferred diet is vegetarian and, not surprisingly, meat eating has been questioned by Tibetan masters across the centuries. Many Tibetan Buddhist communities and lineages were completely vegetarian.
The highly respected teacher, Patrul Rinpoche, said that humans had turned animals into slaves forcing animals to “experience inconceivable torments.” In The Words of My Perfect Teacher, he bluntly outlined the issue saying that animals domesticated by humans are “exploited until they die.” He cited cattle, yaks, horses and sheep as an example noting: “They are milked, loaded down, castrated, pierced through the nose and yoked to the plough. Not one of them escapes this continual round of slavery. Horses and yaks continue to be loaded and ridden even when their backs are nothing but one big sore. When they can go no further, they are whipped and pelted with stones. The fact that they could be in distress or ill never seems to cross their owners' minds.”
Similarly, Shardza Tashi Gyaltsen promoted vegetarianism teaching: “If someone is motivate by desire to eat the flesh of beings, then butchers will seize animals such as yaks or sheep and sever their minds from their bodies. How can those who consume meat and dlood as food be followers of the Buddha? Such people pridefully consider themselves to be benefiting beings and protecting the weak, but their actions contradict the precepts. Meat eating is nothing but the cause of amassing terrifying evil.”