I used to work with someone who had two basset hounds: one was named Fido and the other Rover. Other than that, though, I've never known a real dog named either.You know, I've never met a dog named Rover or Fido.
As for our dogs, we've just sort of let the names evolve. After two or three weeks, whatever we've called them the most is what their official names became. After that, they've usually gone through a whole series of ever-changing nicknames. Our current beagle's name is Mable, and that was the name that the breeder's little girl named her. A couple of weeks after bringing her home, we found ourselves calling her Mable as well, so Mable it was. As for nicknames, she also goes by and responds to Pupper, Gooner, Maybelline, Puppus, Quanzo and Tire Nose.