[yorkietalkjilly]

He's very young and maybe has had a bad scare at some time - possibly during the time his brain was learning about fear and there was nothing to soothe him. I've long heard the theory that nervous or fearful dogs were frightened badly shortly after their brains first learned how to perceive fear - don't know if that's true or not. Or he was just born a nervous dog or your house is really loud, a lot of people come and going, maybe other dogs or cats that scare him or a loud bird that calls out - or - none of those and he's just a nervous dog. Or your vet missed something and he's ill or hurting. Just keep watching him and if he stays this fearful, take him to a different vet for a check-up and consult.

At 12 weeks, he's still a very young baby and very young to have him do anything well on a walk but just learning. Just keep working with him. It takes a dog a long, long time to learn to come 100% of the time when called and the fact that a baby dog doesn't come when called means nothing.

If you had to learn a poem, you would have to repeatedly study and read and say it and it would take you days or weeks to commit that poem to memory. That's how a dog learns to come or walk on a leash or sit or lie down on command - by repetition of having them do it to the command, praising/treating when they do. Over and over and over in little short 5 minutes sessions - for a puppy this young about 2 or 3 minutes sessions - a few times a day and then a big play session and outside to pee.

At 12 weeks, you baby is still learning about life, people and his surrounding and his brain is very under-developed. He has little memory capacity right now but he will get there as he matures. Keep your home calm and quiet and let him grow and mature and settle in and take it slow. Read all that you can about training and how to handle a fearful dog. There is a wealth of good info online and in expert dog handler/trainers' books.