Meaning of "Screwed The Pooch"

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"Screwed the pooch," meaning "made a terrible mistake," is a
cleaned-up paraphrase that author Tom Wolfe popularized. Wolfe's book
"The Right Stuff," which dealt with the early years of America's
manned space program, used the phrase "screwed the pooch" in
describing a calamitous error made by Mercury Astronaut Gus Grissom:

"But now - surely! - it was so obvious! Grissom had just screwed the
pooch! In flight tests, if you did something that stupid, if you
destroyed a major prototype through some lame-brain mistake such as
hitting the wrong button - you were through! You'd be lucky to end up
in Flight Engineering. Oh, it was obvious to everybody at Edwards [Air
Force Base] that Grissom had just f*cked it, screwed the pooch, that
was all."

(from page 230 of "The Right Stuff," by Tom Wolfe)

The original military term (with an asterisk which I've substituted
for a vowel) was "f*cked the dog," which generally referred to
military men goofing off on the job, rather than to catastrophic
errors:

"Screw the Pooch
The phrase screw the pooch, meaning to mess up, commit a grievous
error, was made famous in Tom Wolfe's book The Right Stuff. The phrase
is a euphemism from US military slang. The original expression was
f*ck the dog and meant to waste time, to loaf on the job.

F*ck the dog dates appears in print for the first time in 1935, but in
1918 another euphemistic version, feeding the dog, appears. The
original sense dates to 1918. Over the decades, the meaning shifted to
the current sense and the screw the pooch wording took the place of
the original phrasing."

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