Although your puppy might occasionally wander into a room without you, he'll quickly break down if you leave him alone for even a minute. Your little guy is just afraid and not used to being alone. A crate and positive reinforcement can help him realize loneliness isn't that awful.
While your puppy might think he's king of the household and enjoy exploring new areas, he much prefers the safety and home-like feel of a crate. At first, your pup will probably cry and whine more than he does now when he's left alone, but he'll eventually get used to his new residence while you're away and likely count sheep until you come back. Throwing a safe toy in his crate, such as a tough rope, and giving him a dog bed or blanket to sleep on will help him accept the crate as his den and keep him busy while you're gone.
Slow and Steady
Start the crate training slowly by placing him in his crate and leaving the room for a brief period of time. Don't make a noise. After he's quiet for five minutes, you can go back in and let him out. The next day, don't go back in until he stops crying for 10 minutes, and then 20 minutes and so forth. Some puppies know the difference of when you're simply leaving a room and when you're leaving the house, on account of the front or back door shutting. Once he seems OK with you leaving him alone in the room, you can leave the house and repeat the training process again until he's quiet for about 20 to 30 minutes once you leave. When you do leave for good, make your trips short at the beginning. Leaving him alone for three hours immediately after he's accepted being left alone isn't a good idea. If you're gone for more than four hours, ask a friend or neighbor to come over to let him outside so he can burn off some of his energy.
No Big Deal
Saying something as simple as "be good" when you leave can make your puppy panic, because he realizes he's going to be left alone. And as much as you miss your little guy when you leave, returning home and making a big fuss of it will lead to your dog getting way too excited when someone walks in the door. You want to make your puppy think that leaving and coming back is just a part of life, not a special event.
Aside from being experts at appearing cute every day, puppies are also good at zooming around at max speed and then taking a nap immediately after. If they don't have a chance to burn off their energy by playing and running, they're going to do it by barking and crying. About an hour or two before you leave, play games or take your puppy for a walk. Once you leave him alone, his eyes will feel so heavy he'll have no choice but to collapse and go to sleep.
The sound of a whimpering puppy can melt your heart, but standing strong will help him adjust to your absence. If you go back inside or tend to him while he's whining, he immediately thinks that his actions will lead to you rescuing him from loneliness. On the flip side, yelling at him will never work. He won't understand why you're screaming. To prevent injury, always remove his collar when you leave. Allowing your puppy to walk into his crate on his own accord is always the best practice when training him. Forcing him inside will cause him to dislike the crate.
- dog in a cage image by igor kisselev from Fotolia.com