"The Sims 2 Pets" Keep Pets from Aging

If the life stages for pets are not long enough, you can extend their life by using a new aspiration object. The Kibble of Life object can be bought for 12,000 aspiration points. The downside is that the pets can eat from the food dish twice.

No Aging Cheat Code for Puppies/Kittens

Aging can be turned off from puppies and kittens by using a cheat code. To access to the cheat window: [control] + [shift] + c. Enter the code: "boolprop disablePuppyKittenAging true" to turn aging off. Use false instead of true to start the aging process again.