Violence, dude, I can't believe you ate dog.
Actually, dog meat tastes very good, that's surprising.
No wonder it's a popular meat, especially in Korea (where you can also find cans of "dog's juice" in every supermarket).
But in Korea, they have sometimes the controversial habit to torture the animal, because extreme pain is supposed to tenderize the flesh. This is a tradition I would not give support to, and hence, I try to avoid Korean dog meat whenever possible.
Like with whale, this is my limit. It's not exactly a culinary taboo, it's rather a deliberate choice.
I would not eat the flesh of an endangered specie, especially if it is also known for its high cognitive abilities.
And while speaking of cognitive abilities and ethology, some species of squids are supposed to be
at least as intelligent as dogs. This is why octopus flesh usually contains very high level of cholesterol: it's not fat, it's their voluminous brain and neurons that are disseminated into several parts of their body (rather than being centralized, like in vertebrates).
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As an environmental activist, I would recommanded to eat insects more often. My opinion is not only based on the fact that insects are very common and a cheap source of proteins, it's rather that they probably represent the healthiest possible source of proteins we know. They are easy to digest, and perfectly balanced with every vitamin, mineral and omega acid (unlike beef, lamb, pork or chicken). That's where you see men probably had a long line of insectivorous ancestors, because our intestinal tract is perfectly suited to their consumption: it's a biological fact.