In Men at Arms, Lance Constable Angua goes "plainclothes" to investigate the events at the Assassin's Guild. Gaspode befriends her, helping her both to gather evidence and to navigate the mean streets of Ankh-Morpork. Some of the more important advice that Gaspode dispenses involves the Dog Guild, a sort of beggars guild for four-footed beggars.
Angua initially disbelieves Gaspode -- Dog Guild, yeah right, pull one of the other ones. But she soon discovers the scary truth about the Ankh-Morpork canine underworld. The pair are gang-pressed to a Guild meeting, which was more reminiscent of a Trump rally than a plebium following Robert's Rules of Order. The Guild leader was Big Fido, a small poodle with a high pitched yelp and uncontrolled flatulence. Nevertheless, Big Fido captured the imaginations of the gathered dogs by preaching the superiority of the canine race. He won the rabble's support with rhetoric, but also by executing a guild member who had been caught being kind to a human.
Angua and Gaspode escaped this meeting unscathed, but later ran afoul of Big Fido and the guild. Big Fido -- and his Guild -- petered out when he met an untimely death attempting to pursue a werewolf across rather too large a gap between roofs.