"Screwed the pooch" is the sanitized version (for print and movies) of what they really said... which was
"F _ _ _ ed the dog"...
http://answers.google.com/answers/threadview?id=350436Originally meant military men goofing off on the job, rather than to catastrophic errors:
Anyone who has ever been in the military has spent an inordinate
amount of time in a 'stand-by' formation waiting for someone to get the orders to start some activity. Many man-hours were spent in an activity that was commonly known as 'Effing the dog.' [Note: They didn't really say, 'Effing,' but I'm sure you can figure it out.] Back home in civilian life this was cleaned up to the slightly more acceptable 'screwing the pooch."