IF you bought My First Pet Stuff...

Yes. I tend to incorporate packs slowly into my game and this time it's not different. My current household I'm using a rat, and some cat items including a pet bed. Since there is only a young adult and his pets I've used nothing else in game play. I've pulled all the stuff out on an empty lot though and already know where I'm using much more of the "stuff" when I swing back around to other households, and I made a new sim girl in CAS for the hair. It might take awhile to get around to using most of it though I'm in a sweet spot with current family and just really enjoying playing them. Part of the reason I love these packs is for inspiration ... and it delivered for me.
I am really enjoying the rat and although many probably would hate to hear it, I wouldn't feel ripped off if it was just that.. the animations between the sims, cats and dogs and the rodent and of course the disease/death/ghost process.