Below are the list of achievements for one of the DLC's, which is released on 31st August 2010. Achievements for the 360 version were implemented almost a week after the DLC release. There are 9 achievements worth 250G and 9 trophies, with 6 bronze and 3 silver trophies.
[Doggie Bag] Get 5 kills using canisters in a round of Multiplayer Ranked Match or Arcade Mode.
Escape From The Pound
[Doggie Bag] Escape on all levels at least once in Multiplayer Ranked Match or Arcade Mode.
[Doggie Bag] In the last round of a 'Fragile Alliance' Ranked Match, climb from last to 1st place.
[Doggie Bag] Escape with $100,000 or more in every round of a Multiplayer Ranked Match Session.
The Dog Track
[Doggie Bag] Escape in less than 1 1/2 minutes in Arcade Mode or Multiplayer Ranked Match.
[Doggie Bag] Get 150 criminal kills as a cop in 'Cops & Robbers' Ranked Matches.
Last in Show
[Doggie Bag] Escape as the last player on your own in a Multiplayer Ranked Match.
[Doggie Bag] 100 kills.
[Doggie Bag] Accumulate $25,000,000 during your career in Multiplayer Ranked Matches.