"The Sims 2: Pets is the fourth expansion pack in The Sims 2 series of games, as well as a stand-alone game for several consoles. It is published by Electronic Arts. The Sims 2: Pets was officially announced on July 26, 2006 and released on October 18, 2006 in North America and via digital download, as well as on October 20, 2006 to the rest of the world, except for Australia/New Zealand, where it was released on October 26, 2006. Aspyr released a port of the game for Mac OS X on November 7, 2006."
Source: Wikipedia, "The_Sims_2:_Pets," available under the CC-BY-SA License.