All names are renowned owners of dogs. Their dogs are:
Shaggy - SCOOBY-DOO (from Scooby-Doo)
Dorothy - TOTO (from The Wizard of Oz)
Martin Crane - EDDIE (from Frasier)
Irving Hillman - VIVIAN (from Cathy)
Mooch - EARL (from Mutts)
George Jetson - ASTRO (from The Jetsons)
Wendy Darling - NANA (from Peter Pan)
Obelix - DOGMATIX (from Asterix)
Finn - JAKE (from Adventure Time)
Travis Coates - OLD YELLER (from Old Yeller)
Spike Spiegel - EIN (from Cowboy Bebop)
The first letters of the dogs' names spell out STEVE AND JOE. Again, Steve and Joe are renowned for owning a dog, and their dog is BLUE, the answer to the puzzle.