Bernard is obviously a saint's name, but how did it get to the big, benevolent dog? The eleventh century monk, patron saint of mountain climbers, who lived in the Alps, was famed for setting up safe houses for pilgrims on their way to Rome over the treacherous St. Bernard Pass, and the canine breed, also used to rescue people in treacherous conditions, was named for him.
Over the years, though, the name has taken on a highly intellectual image, losing most of that old Alpine energy. There were lots of little Bernies in the early decades of the twentieth century, though--Bernard reached as high as Number 45 in 1921.
And the name does have some cultural cred, via playwright (George) Bernard Shaw, seminal art historian Bernard Berenson and novelist Bernard Malamud.