Do you have to have sims 2 pets to have a cat or a dog in sims 2?

No, you can not play Sims 2 Pets without Sims 2. You either need Sims 2, Sims 2 Holiday Edition, Sims 2 Deluxe, Sims 2 Double Deluxe. Since Sims 2 Pets is an expansion pack, you need to have at least one of the following of the sims 2 i mentioned above. All of them have the regular, basic Sims 2. Hope this helps you!!