As early as possible, the puppy needs to learn that being alone is not a bad thing, particularly while you are at home, or about to leave the house.
Below are some exercises you can do to help your puppy be O.K. being left alone – but make sure after each of these exercises that you do not allow your puppy access to you if it is whining, barking or showing signs of stress. Wait at least 10 seconds after any signs of stress before allowing the puppy access to you.
Tie up your puppy on a short lead to something solid that is near you, close enough so the puppy can see and smell you, but far enough away so it can’t touch you. Gradually walk further away from your puppy. You don’t want to push it too far too quick, you want the puppy to feel comfortable but also realise that it cannot get to you. Perhaps after fighting with the lead for a minute or two it will realise you’re not going anywhere and stop stressing.
If the puppy is walking around the house following you, shut a door behind you, leaving the puppy in the next room, even for as short as 5 seconds, then open the door and ignore it like it was just a silly mistake. You can gradually increase the amount of time you leave the puppy in the other room. Once again, don’t try for too long immediately. You can even put the puppy in and out of a room multiple times for short periods of time. The first couple of times it may become a little anxious but soon it will become bored of the game and stop worrying about the door opening again.
Try getting your puppy to sleep in a nice, cosy, lockable crate. Begin with the crate in your bedroom and once the puppy is comfortable sleeping in the crate there, you can gradually (perhaps a metre each night) move it away from your bed until it is sleeping somewhere that is a decent distance away from you.
When leaving the house for long periods of time, like going to work or school, the last thing you do before leaving the house should be giving the puppy something fun to do like scattering its breakfast through the yard, giving it some frozen treats or a huge block of ice, giving it new safe toys, smearing food on some toys, or something safe and fun to destroy! Make sure it is the last thing you do, so while you are walking out the door or the puppy is hearing your car drive away, it is already doing something fun!