They have names that could make a random password generator cry uncle. Meet, for example, GCHG CH Calicops Sassafras Gonnakikurass. “She’s a saucy girl. Her name says it all,” Fred Ortiz said as he groomed the Brussels griffon to compete Monday at the Westminster Kennel Club dog show.

Westminster Kennel Club Dog Show features more than 2,500 dogs from around the world competing for the coveted title of Best in Show.

Louis, a 7-year-old whose full name is GCHP Sunlit’s King of Queens, showed no signs of nerves. He eyed interlopers at a haughty remove. He yawned in the face of commotion. “This dog is the most confident Afghan hound I’ve encountered in my entire life,” Ms. Jones said.

Dogs have begun vying for the big prize — best in show — at the United States' most prominent canine competition: the Westminster Kennel Club dog show.