Direct participants in cock fighting have told me drugging with steroids and painkillers was/is? routine.
Years ago the blacksmith where I worked in Texas was a very active participant in the \'sport\'. He was routinely flown all over the world, Phillipines, Mexico and Central America,etc. with a group of his birds to fight. Wealthy patrons would pay all his expenses round trip. Crossing international boundaries with his birds was \'facilitated\' by his patrons.
The betting was astronomical.