(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.
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.”