"Dog my cats"

An afternoon conversation's question: Who said that?

I remembered it from some cartoon, but couldn't remember which one either. (Pogo) And what did it mean? Obviously a dramatic interjection, maybe a "minced oath". If it's the latter it doesn't mean anything exactly, but maybe the first does?

Searching the infalible internet turns up the claims that the earliest known reference is in Huck Finn (or by O Henry decades later, through some amazing time warp).

Suppose the phrase is literal and the key word is the verb "dog". "Follow my cats around" isn't a compelling image. "Latch down my cats" has an arrestingly chaotic feel to it; I could almost believe that one. A random internet-er held that "my great-grandfather said" it was a sarcastic "Sic your dogs on my cats" to someone being too aggressive--um, maybe, but again it doesn't seem compelling.

I suspect the majority is right, and it was a euphemism for "damn my something-or-other". But I like my little folk-etymology.