The Sims 2: Pets/Pet Ages

Pets are just like Sims. As time goes on, they age, the only exception being that they cannot use Birthday Cakes.

From the Create-A-Pet menu, you can choose to make an Adult or Elder pet. When pets are born, they are puppies or kittens, but you can only get then by breeding your pets or adopting one from the pet adoption centre.

Puppies and Kittens
Time till Birthday: 4 Days

Your Sims can interact with puppies, although much like Adult and Elder pets, you cannot control them. Your Sims can praise or scold puppies for doing things, but you cannot teach them commands or command then to do anything. You also can't scold or praise them for being on sim beds, as they are too small to get onto the bed, but you can praise them for being in the pet bed.

Puppies and Kittens (much like Toddlers) don't have all the needs of their Parents. Puppies don't have to Chew, and Kittens won't go crazy if they have nothing to Scratch. They also don't have a hygene need, as they are to small to get in the bath. But they do have to eat, sleep, interact with other sims and pets, go to the toilet and have fun.

Puppies and Kittens (like Toddlers) cannot go up or down stairs, so if they arive in the garden and their pet things are upstairs, make sure to bring them to their room becaused otherwise you'll loose them to the adoption centre.