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While the character of Brother Juniper was named after a historical figure, the St. Bernard shown here was not actually named after a Catholic saint. It was named after a hospice in Switzerland, where they were first bred to rescue people. The hospice itself was named after St. Bernard of Menthon (not the more famous Bernard of Clairvaux). In doing a little research on the dog breed, I was unfortunately unable to find anything about their ability to sing or harmonize with bells. I did find that the most recently the dog was used for rescues was 1955, years before this comic was published. This means that the dog pictured here is not a rescuer, and it's possible he is actually employed mainly as a singer. The barrel, therefore, must be where he keeps his sheet music.