Moose was born on Christmas Eve, 1990 in Florida, the youngest littermate. He was the largest puppy in the litter. Like Pal, the original Lassie, the obstreperous puppy was too much for his original owner. According to an article by Lori Golden.
In fact, chasing cats was one of the activities that led to this troubled terrier becoming one of TV’s most precious pooches. Originally owned by a Florida family, Sam and Connie Thise, Moose was too hard to handle. He couldn’t be house trained; he chewed everything; he dug and barked a lot; and he was constantly escaping and climbing trees. Eventually given to the Florida manager of Birds and Animals Unlimited, a company that trains animals for TV and motion pictures, Moose was put on a plane at 2½ years old and sent to Mathilde DeCagny, an LA trainer working for the show-biz animal company.
Moose won the role on Frasier after only six months of training. Moose had the ability to fix Kelsey Grammer with a long hard stare; this became a running sight gag on the show. When Moose had to lick his co-stars, however, sardine oil was applied upon the actors' faces, John Mahoney once revealed liver pate was dabbed behind the actor's ears to make Moose nuzzle the actors.
During the height of Frasier's popularity, Moose received more fan mail than any of his human counterparts.
Moose has numerous television appearances and several magazine covers to his credit. There is an official Moose calendar and an "autobiography", My Life as a Dog, which was written by Brian Hargrove, husband of Frasier actor David Hyde Pierce.