Trivia heard from a retired naval aviator friend (unless he was having me on).

Pilots, when on an aircraft carrier are in something called a 'ready room' for pre-mission briefings. Those rooms often have soft-serve ice-cream machines. Usually, it's a single machine serving chocolate. The pilots refer to what it extrudes as 'dog sh*t' - usually shortened to 'dog', as in "hey, want some dog?".