This is not legal in most places but theres talks of other animals fighting so why not ask.
I know it is popular with Bitcoin and gamblings.
In my country it is legal to bet on animals fighting but I don't think people really do bet on a dog fight here. I have watched competitions on dog fights but it is not something I really will like to bet on as I see it as animal cruelty! Some people may see it otherwise but I do pity animals especially when human beings are taking advantage of them.