running dog 
noun
1 informal A servile follower, especially of a political system: the running dogs of capitalism...
- Gone are the days when China's media would issue stern warnings against Western habits imported by the running dogs of capitalism.
- For decades, the party railed against people it called running dogs of capitalism.
- Make those rapacious arms dealers, those running dogs of capitalism, pay you some serious money.
Translating Chinese zǒugǒu
2A dog bred to run, especially for racing or pulling a sled.A good running dog will ‘pull’ you along at a faster clip than you might be able to manage without it, giving you a better workout....
- If fast running dogs such as greyhounds or lurchers were used to hunt foxes, the whole thing would be over in seconds, but then there would be no ‘sport’.
- Because if you're a running dog like a Greyhound you have huge muscles in your pelvis and you've got to have thin legs or you'll never move them, just like a racehorse has to have thin legs.