Here's one take on Fire Dogs (quoted below from http://www.astrologycom.com/firedog1.html) :
The Dog in Chinese astrology expresses its principle qualities of loyalty, faithfulness and unselfishness. The Dog is active and honest and is appreciated by his superiors and those under him due to giving priority to the collective interests of all rather than his own. His best role is as a prophet of future events and he barks to draw attention to the events of the day as well as to the injustices of the world. He does look to how wrongs can be corrected. He's forever on guard to look after his property and so anxiousness is a characteristic of his personality. Money is important for his family and so he will earn it to support them; however, he thinks of it as mere 'paper'. He delights in anything to do with the occult, the mysterious, the bizarre and the unusual so he yearns to investigate these things in his life.
Wild and RomanticThe Dog's favourite places are wild, romantic landscapes and the remote regions of the world. He feels at home in the wilds of Tibet or Mongolia, the windswept islands of Scotland and the jungles of the Amazon. For this reason he is an explorer, but he also prefers the comforts of peaceful evenings by the fire where it's far from the business of the everyday world. As a profession he is suited to be a manager or head of companies, but he cares very much about the quality of the work. He can be a priest, nun, missionary, teacher, nurse, magistrate, judge, lawyer, doctor, scientist, researcher or preacher. More than any other animal of the zodiac, the Dog is always asking itself, "What am I doing here on earth and what is my purpose in it all?"
A special feature of the Dog-born person is that he or she is the one who sits at the gates awaiting nightfall, wherein the Dog will prowl and keep watch. He is a faithful watchdog and is the guide and guardian in the underground invisible worlds and thus, lying at the gates of the underworld, is a figure of the subterranean world of life and death and is symbol of initiation into the rites of death and rebirth. He pleads mankind's cause with the gods and especially brings questions for us all about our life purpose. Cerebus, of Greek mythology, was the dog who lay at the cave entrance by the River Styx, the river that souls crossed in their passage from life to death, guarding the Gates of Hell and Pluto's underworld. In the Egyptian Book of the Dead it was the dog who guided souls on their journeys into the next world. This year then, will bring a certain edge to us questioning why we are all here.