Green’s Dictionary of Slang

a mild oath, a euph. for what the dickens...? phr.

1787		R. Tyler Contrast II ii: But what the dogs need of all this outlandish lingo?
1836		T. Haliburton Clockmaker I 232: I don’t know what the dogs to put him to. [Ibid.] 284: Well, says I, what the dogs has become of my horse.