THE SIMS 2 PET

no, you can't play the sims 2 pet without the original sims 2. becuz the sims 2 pet is an EP. (expansion pack) it doesnt support the game without the sims 2.

suggestions:
install ALL the sims 2 EP by this order:
1) The Sims 2 (original)
2) The Sims 2 University
3) The Sims 2 Nightlife
4) The Sims 2 Back to Business
5) The Sims 2 Pets.

also, there are lots of more news and information from its official website: http://www.thesims2.com
it is very helpful. CHEERS!

happy simming!