Dogboys (1998)

Marine veteran and former middleweight boxing champion Julian Taylor loses control in a bar fight and ends up serving time for aggravated assault. Soon after his arrival, Julian is introduced to Captain Brown, a menacing, overbearing guard who tags him "Dogboy" and orders him to a claustrophobic dormitory called the doghouse. There, Julian meets fellow inmate Willy Owens and learns that the prison's vicious attack dogs are used to catch and kill escaping prisoners.