Has anyone ever actually seen Ranger and Krypto in the same place at the same time? It seems like whenever Krypto is around, Goldie is convienently off picking up some dog treats missing all the action. But the idea that Ranger could secretly be Krypto is laughable- I mean, Ranger is just a mild-mannered clumsey unathletic family dog from California who spends time with some reporter turned farmer, and Krypto is a muscular flying dog from Krypton who spends time with Superman...
Plus, Krypto has laser vision and can see through walls, and Ranger has those big gawky dog glasses...
Superstar reporter Lois Lane lives under the same roof as Ranger, and has shown no indication of noticing that he is fact Krypto, and it'd be unprecedented for her to miss the fact that some mammal she sees every day is actually a superhero in disguise if it were true. I mean, she's won a Pulitzer Prize! All Ranger wants is a little attention, but she's always off following Krypto's adventures...