Rounding up a few minor appearances from late 1961, the biggest of which is from Lois Lane #30, in which Superman is forced to teach Lois a lesson about her recklessness. He's not always going to be there to save her, and she takes the invulnerability he affords her for granted. Krypto's role:
In Superboy #93, he's used by the antagonist to deliver a message to Superboy... never could resist a delicious aroma.
In Adventure Comics #292, Krypto chases meteors, once helping Superboy discover a new element: