The owners had to be able to handle the dogs long before they ever got into the ring, they had to be fed, excercised and everything else. Before they fought they would be put on "keep" sometimes other people would keep their dogs. Basically it's the a special diet and exercise 2 months before a fight. This would be nearly impossible with a human aggressive dog. Once in the ring there in with a ref and have to be handled by a handler( owner or someone he hired) between rounds. After 3 wins, then they could be registered. Reading the history they just say the others were culled, I'm assuming this means killed. I've never been to a dog fight personally, I find it cruel. I do like chicken fighting though, even in chicken fighting, human aggressive birds are very undesirable because they're dangerous in the ring and usually get murdered
