Krypto, why are you hounding Superman at Perry White's beck and call?! It happened in Action Comics #287, when a narcoleptic Superman started causing mayhem. Well, it's all a bad dream from which Superman is eventually awakened by Krypto's super-licks.
But let's go back a month to Action Comics #286, where this scheme actually started. And Krypto was part of its inception.
Now I'm going back to sleep.