"The reason why dogs are beaten for so long is that there is a belief that the slower & more painful the death is, the more potent the dog's meat will be. Killing the dog slowly causes the dog's adrenaline to flow, & this flow of adrenaline throughout the dog is believed to increase the aphrodisiac power of the meat.
While the dog is slowly being killed, it is of course screaming in pain, and trying to resist the grip of the man doing the killing. One method is to tie the dog from his hind legs upside down. The man or men than beat the dog's body all over with clubs or bats. Beating it this way is said to do 2 things. One is to increase the flow of adrenalin and the other is to tenderize the meat.