Here is a post I made a while back when this question was asked...
unfortunatley there is no quick fix for this.
It is going to take a lot of time and patients and even then it may not work and you will just have to except that you have a dog who dosn't like loud noises.
Is there anything specific in the dog's past that you know of that may have caused this to begin with?
if so avoid that like the plague.
Here is a post I put up a couple months ago about how to introduce a dog to gunfire you can you the same method here i believe
Quote:
You usually only get ONE chance to make a dog comfortable around a gunshot. Because once they are scared of it thats a tough knot to untie.So don't rush it.
They may be born not afraid of guns and you can shoot around them anytime ,but thats not a chance I would be willing to take with my dog
That said... This is what you do.
With you holding the dog and loving and praising the heck out of him till his tail about waggs off, have a partner take a small caliber gun like a .22 and got about 50-75 yards away. shoot a couple times... come 10 yards closer... shoot a couple more times... come 10 yards closer, repeatuntil they are standing right next to you. The whole time you are loving the dog up and telling him what a good boy he is... Treats won't hurt either.
Let a day or so pass...
Then if you have a small gaugee shotgun available .410 or 20 gauge repeat the above process.
Let a day or so pass...
Finally repeat again with a 12 gauge.
If at any point the dog shows any sign of fright, STOP and slow down, go back to the smallergun until you are certain he is comfortable,if you sense you should stop for the day DO IT, there is always tomorrow.