[quote=Gyson]?nless it says right on the item FOR THE DOG or something like it, it is impossible to know enough to open up your inventory and have the dog interact with anything in it.
I think you need to stop playing this game and go play Skyrim or Amalur or some other game where the quest pointer always shows you where to go next and where every item tells you what it's for and where lateral thinking is not required. It doesn't sound like D:OS is your style of game.