Consider this: Your pup has just spent the first 8 weeks of his life in the company of his litter mates and mother. He comes to your home, and because he is so cute you spend an entire week with him before your life returns to normal and you return to your everyday routine, leaving your pup on his own (for the first time in his young life) . Spending time with your pup is a good thing as it strengthens the bond, BUT you can have too much of a good thing and puppies need to understand that being alone is OK.
If puppies are not taught at an early age that being left alone at home is not a bad thing, symptoms such as digging, barking, destructive chewing of things like furniture and other things can appear. The best way to treat separation anxiety is to train the pup from day one so that it never becomes an issue. Once your pup has settled down in his new home, you can start this part of his education by picking up your keys and calmly stepping out the door, closing it behind you. Before your pup even starts stressing, you step back into the room and give him a treat. Continue this, adding more time as you go along, until your pup is being left alone for an hour or two without fussing. He will soon realise that his people are coming back and that he is being calmly rewarded on their return.
Often what happens is that you unthinkingly contribute to the puppies anxiety by making a production of leaving and returning. The very best thing you can do to alleviate your pup’s stress levels when left alone is to simply make leaving and returning a non-event! Owners often reinforce bad behaviors and contribute significantly to their dog’s level of distress without even realizing they are doing it.