Origination

So today, I found myself talking to my dogs--as one might do when at home 4 days in a row mostly alone. Cole (the doberman), took my seat. I looked at him and said, "move it or lose it, buddy." And then I wondered, what the heck? Where did that come from and what does it mean? "Move it or lose it." Lose what? "Move your meat, lose your seat" is directed at the person whose seat you took, but "move it or lose it" is for the person/dog that took your seat. Why? "move it or I will physically move you"?--as in the case with the dogs. Is it an empty threat when directed to a person? Where did this come from?

Any ideas?