Origin of expression

As I understand it, a “shaggy dog story” is one in which the story meanders aimlessly for an extended period of time, focusing on insignificant details and asides, and never actually reaches a point.

It is not immediately intuitive as to how that label would come to describe this sort of story. The best explanation I can think of is that a shaggy dog has an abundance of hair (c.f excess detail) and a relatively small body (c.f. the point of the story). But this seems like a somewhat strained analogy, and not the sort of image that would naturally think of when hearing a story like this. And while meandering and focusing on insignificant detail are oft-seen traits in our canine friends, there is no reason to single out the sartorially blessed breeds at the expense of, for example, the chiuaua.

Does anyone know where the expression “a shaggy dog story” originated? Is there a canonical “shaggy dog story” that is actually about a shaggy dog?

(Points will be deducted for references to Disney’s The Shaggy D.A. and bad puns about the insipid plotlines of old Scooby Doo episodes.)

Here’s a detailed response from World Wide Words (http://quinion.com/words/qa/qa-sha1.htm):

The first shaggy dog stories seem to have been variations on a tall tale that was indeed about a shaggy-haired dog. Eric Partridge wrote a little monograph called The ‘Shaggy Dog’ Story, Its Origin, Development and Nature in 1953. He said that “the best explanation of the term is that it arose in a story very widely circulated only since 1942 or 1943, although it was apparently invented in the 1930’s”. The term itself is even more recent than those dates: the first reference I’ve found is to a piece by David Low in The New York Times Magazine in 1945. An obscure collection of shaggy dog stories under that title was published in 1946.

There are many candidates for the original or ur-shaggy dog story. William and Mary Morris, in The Morris Dictionary of Word and Phrase Origins, give a version of it that involves an advertisement being placed in The Times to announce a competition to find the shaggiest dog in the world. After a vast amount of effort and investigation (described in detail, after the nature of this type of story), the winning dog was presented to the aristocratic instigator of the competition, who said: “I don’t think he’s so shaggy”.

Eric Partridge gives another version as the original. A grand householder in Park Lane, London, had the great misfortune to lose a very valuable and rather shaggy dog. He advertised repeatedly in The Times, but without luck, and finally he gave up hope. But an American in New York saw the advertisement, was touched by the man’s devotion, and took great trouble to seek out a dog that matched the specification in the advertisement and which he could bring over to London on his next business trip. He presented himself in due course at the owner’s impressive house, where he was received in the householder’s absence by an even more impressive butler, who glanced at the dog, bowed, winced almost imperceptibly and exclaimed, in a horror-stricken voice, “But not so shaggy as that, sir!”

shaggy-dog story – A long, drawn-out anecdote depending for humor upon an upsurd or anti-climactic punch line. – TAH Dictionary
Sorry, no etymology cited. Lemme check another dictionary.

BTW, Fred MacMurray was a god. As is Shaggy.