I only have the ball, bone, and duck. My pet 'Pipi' is 7 years old and I play with her all the time. How long before my other 'stuff' will be unlocked?

the locked boxes will unlock as your game progresses. Use what you have currently to keep him happy, and you'll see new things as he ages.

Thanks for that. About what age will they unlock?

well, that's a secret!! You don't want to spoil the game now do you?? If you would like to know, send a PM. Here is the link for information: help with puzzles