I don't think they would make a pack that has to do with dogs/cats, as it requires that people own Pets (and I don't think stuff packs usually depend on people owning pre-requisite packs). However, a small pets system could be completely separate from Pets in that it wouldn't require you to own Pets to play. It could be a small collection of interactive object "pets" along with the usual decorative objects we usually get in a stuff pack, rather than modifying the existing dogs/cats which require animations, routing, detailed interactions with Sims, etc.
