Kelham said the Northern Inuit dogs originally had some traces of wolf in their bloodline, but that it has been bred out over the generations as they have been mixed with other northern dogs such as huskies and malamutes.
"They are very, very docile," Kelham said. "They don't make good guard dogs. They are great with kids, great with other dogs."
During the first two seasons of Game of Thrones, live dogs were shot against a green screen that allowed producers to add in visual effects behind them, as well as expand their size and smooth out the edges, according to Jason Zimmerman, creative director and visual effects supervisor at Pixomondo, a Burbank, Calif., studio. Pixomondo created the dire wolves in season 2 and is responsible for the show's dragons as well.
"You can't beat the real thing photographically," Zimmerman said. "You are looking at something that doesn't trick the eye because it is a real creature."
During Season 3, which began last month, the animals have become much bigger as the storyline has progressed and the animals have aged.