I agree something "new" has happened to the dog. After five years he should get excited and ready to work whenever he hears gunshots.

Likely much more to this story than you currently know about.

Well being honest I have never seen the dog hit during training. That being said I am only a volenteer they call when the really need some one to wear a bite suit or sleeve and am no expert at all.  What they do when I am not there or have done in the past I have no idea.

 The dog had his teeth cleaned a few days before, and this was their first time back in action? Could that have triggered it?

I have never had a dogs teeth cleaned so I don't know how it is done.

If it is done with some sort of drill or power instramint, and the the dog was physically restrained, or somehow traumatized by that then hell yes it could have something to do with it.

They anesthetize the dog once he is sleeping they clean the teeth just like a human dentist cleans our teeth.

Ok well probably not then.

Good luck and let me know what happens.

Get A Real Dog was right! The dog started limping front left paw that night after I posted this , the vet pulled out the wading from the blank from in between the webbing in the dogs toes. I went out and watched them train today and the dog was acting like it never happened. They also got a new blank pistol  hat has a plugged barrel.

Oh Jesus, don't post that he was right for him to see! Now we'll never hear the end of his all knowing ego! LMAO 

Taking a bow........

Glad to hear it worked out and the dog didn't get severly injured,or washed out for something like that. I have seen it happen. The fact that the dog recovered mentally so quickly show it is a good dog. Resilliance is something often over-looked and not regarded as highly as it should be.

While taking that bow, watch your ass, it's prone up in the air like that!