Aussie refuses to walk

Question
Hi - we have a 12 week old male Australian Shepherd puppy who is having trouble walking on a leash.  I think I may have been too strict on him at first - but his behavior on the leash from the moment we first put it on him has been just terrible.  Grabbing, tugging, refusing to move, etc.  

He shows signs of fear on the leash (ears go back, etc).  The best success we've had is to take him for a walk together.  We try a great deal of encouragement etc.  He can sit just fine.  We slap our leg, wave our arm and lead with our left foot and encourage him with an excited "let's go".  Sometimes he goes - sometimes he just sits there.  

When he bites the leash we shake his muzzle and say "leave it" in a stern tone.  He understands and drops it - then picks it up immediately again.  After a few minutes of testing us he usually quits that behavior.  We are at the point we don't have to shake his muzzle, we can basically issue the command and he will drop it.

If my wife takes him out on the leash he is better than he is with me.  I'm afraid he may be associating me with too many negative corrections.  Is there any way for me to "retrain" this behavior?  Thanks in advance!  

Answer
Hi Don,
A good way to get your dog used to a leash is to leave it on him in the house.  Just let him drag it around and he'll learn that it is not a bad thing.  You may have a leash or two chewed in the process....
Also, start out with very short walks.  Maybe just the length of a yard.   Get a real yummy treat like a liver treat or even a piece of a chicken breat.  Hold it in front of his nose as an encouragement to walk.   Just go slow and don't push him.  He'll get it in no time and will love his walks.   Definitely don't punish him for not wanting to walk.  He is young and still learning.   If he is already showing signs of fear for you, I would never yell or scold him other than a firm no when absolutely necessary.  Use only positive reinforcement.
WHen you have a minute, check out www.paw-rescue.org and look for Robin's pet tips on the home page.   You will find many useful training tips.  With a dog just 12 weeks of age, you'll probably be needing a lot of the tips she has included on her site.