Example usage:
"Jim, that shipment was supposed to go out thirty minutes ago, quit fucking the dog!"
or
"Hey what are you up to right now?"
"Oh, nothing, just fucking the dog."
or
"Isabelle hardly gets anything done, she's a real dog fucker."
or
"My manager at work just fucks the dog all day, I have never seen him do anything useful."
from the Northeast, can't say I've ever heard this. "Screwed the pooch" means someone made a huge mistake, but never heard it (or fuck the dog) to mean wasting time. Completely possible it's more prevalent in the South or Midwest.