well, dog my cats

(well,) dog my cats

1. An exclamation of surprise or incredulity. Well, dog my cats! I never thought I'd see you around these parts again!
2. A mild, inoffensive oath. Dog my cats if I know what we're supposed to be working on here.
See also: cat, dog
Farlex Dictionary of Idioms.

well, dog my cats

An expression of astonishment. “Dog” may have been euphemism for “damned,” as in “I'll be doggone.” “Cats” might have been just something opposed to “dog.” The earliest written reference is in O. Henry's 1910 short story, Memoirs of a Yellow Dog: “I began to feel sorry for Hubby, dog my cats if I didn't.”
See also: cat, dog
Endangered Phrases by Steven D. Price
See also:
  • (well,) dog my cats
  • Well, bust my buttons!
  • (well,) bust my buttons
  • Well, shut my mouth!
  • (well,) shut my mouth
  • get out!
  • get out of here
  • Get out of here!
  • Ye gods and little fishes!
  • Ye gods!