Also, I get your point, and where you are coming from, but you know all pets, dogs and cats and so on, once were just wild animals... Human would never had live this way if they didn't worked closely with wild life in first instnce. Now you can be against it, don't have pet, hunt game meat, or go vegan cause in your opinion it's not nice and you better leave the medecine, working associates ( working dogs, horses etc ..), but you'll not chage the human history, and prehistory, that is lined to animals, and plants. Even your daily veggies were wild and been "domesticated".
I wuold anyway not breed one to have a drug machne to get high. You can grow pot for that. Buy cheap ethanol and do a ot of things. Toad and frogs secretions, as well as my pet leeches who actually use my blood, bite me and all, are highly therapeutic. You certainly missed this point here. But yeh, so are most animals venoms, secretions and of courses plants and mushrooms ...
II think philosophically, you can't say it's selfish to breed any animal, or hunt or breed them. Bees are going extinct too, as exemple, is it better to leave it doing it's death or still ok, to beekeep ? Of course extinctions can be seen as natural, but I think human being are being used by a host of microorganisms and animals and plants, but you think you are too conscious to play consciously the game of life. Better feed off Prana. Then, yes, you'll just be food and tool. But still, you'll breed bodily bacteria that don't need food but you.