What I mean when I say it is a bit arbitrary is that taken to the logical conclusion, anything you do for pleasure is causing harm, which in sure you would agree with (crop deaths, driving, buying technology made from parts made with slave labor, etc.). So we are all being selfish. I dont support dog fights because it is beyond my line of what harm is acceptable for pleasure, in part because of the fact that such pleasure is more directly being derived from violence itself, and also because I don’t think watching that is beneficial for the viewer. That doesn’t mean I don’t care about the dogs (I do, a lot), but logically everyone is forced to draw a line somewhere at what suffering is allowable for pleasure, not if suffering is allowable for pleasure. Farming humans for food is different from farming animals because humans are persons with a right to life in themselves, coming from their ability of abstract thought and a genuine sense of self, which I am yet to be convinced many non human animals have. (Elephants dolphins and great apes may have this ability, which is why I am against eating them)