I think having it online is a very great idea, though I am yet to identify any site that does it but I belief the information would be released soon and this might even be a good reason for some already existing casino sites to make provision for cock fight betting. It's from here we would know the casino sites that are concerned about the needs of their players and ready to deliver. It will be my utmost pleasure to play on any site that offers this service.
You will not find Cock fighting on an online betting sites because this sports is not popular and is limited to very small population / people of the world. Mostly the gamblers who bet on this cock betting are traditional gamblers who manually bet on these fights. In most places it is illegal and be considered as an abuse of animals. Many NGOs may consider these fights as violation of rights of the animals.