Off the Chain traces the American Pit Bull Terrier from its origins as a working and fighting breed to its present reputation, and follows the underground culture of dog fighting that still surrounds it in the United States. The film moves between breed history, the legal fight against organized dog fighting rings, and the dogs themselves, many rescued from fighting operations and shown in the aftermath of that life. Breeders, rescuers, and people connected to the fighting world speak on camera about why the practice persists despite being a felony nationwide, and about the gap between the breed's temperament and its image. The film treats the Pit Bull's reputation as something built by people rather than inherent to the dog, using its subjects' accounts of raising, fighting, and rehabilitating the same animals to make that case.