Historically, dogs were workers, bred to function as guards, hunters, shepherds, trackers, and beasts of burden. Surprisingly–to me, at least–the concept of a dog as a pet didn’t evolve until the early twentieth century. The canine star, Rin Tin Tin, is a fascinating case in point. I just read Susan Orlean’s book, Rin Tin Tin: The Life and the Legend, and recommend it highly for anyone interested in dogs or in the Roaring Twenties.
The German Shepherd was a “new” dog in the Twenties–the breed had been developed only a couple decades earlier (guess where) and introduced into the United States after World War I. American soldiers came home with stories about this smart, brave, and loyal breed, and a few of them, like Lee Duncan, brought one home with them.
Lee Duncan (center) with Rinty
Duncan found a puppy in a ruined German kennel, named him Rin Tin Tin (Rinty for short), and took him home in 1919. Astounded at how smart the dog was, Duncan trained him and then shopped him around to the Hollywood studios until one–Warner Brothers–signed Rinty up for a movie. 
He acted so well in small parts in two 1922 films that he was given his first starring role in a 1923 feature film, “Where the North Begins.” After that, he cranked out features until he died in 1932 at the age of fourteen.
Jack Warner had been leery of animal actors ever since he’d been bitten by a monkey, but he quickly came around after Rinty’s phenomenal success. Daryl Zanuck wrote the screenplays. Warner paid Rinty $1,000 a week at a time when human actors made $150. Someone figured that in eight years, Warner paid Rin Tin Tin’s owner the equivalent of $5 million. There is little doubt that Rin Tin Tin movies kept Warner Bros. Studios from going under. In fact, Jack Warner called the dog his Mortgage Lifter.
But Rinty was not a pet in these films. He was a a companion, a co-worker. He was rarely shown indoors. He wasn’t playing a role; he was playing himself. (Later, the many different male collies that played Lassie were portraying a fictional female dog made popular in the novel, Lassie Come Home.)
Rin Tin Tin astonished audiences with his physical feats. He climbed a tree, he leaped 12-foot walls, he fought bears. And he “acted.” His expressions showed sorrow, anger, and happiness as well as any human actor, and in silent movies, his lack of speech wasn’t a disadvantage. Soon, German Shepherds were the most sought after breed in America, and Rinty’s pups started at $250, the rough equivalent of $3,000 today.
According to Susan Orlean in Rin Tin Tin: The Life and Legend, dog training started in Europe, as did obedience competitions. These concepts came to the United States in the twentieth century. Before then, owners simply didn’t train their own dogs. They sent them to professionals to train as hunters or shepherds or whatever. Professional handlers trained dogs in schools for several weeks or months, then returned them to their owners with instructions. 
