Introducing your new pup to gunfire is one area you have complete control over in the development of your gun dog. I believe gunshyness is manmade. Animals are naturally afraid of loud noises and it is up to us from the very first day we bring the pup home to condition him to not be afraid of gunfire and in fact, learn to love it.
From day one we can set pup up so that she learns to associate loud noise with pleasant things, things that she likes and does not fear so that as she gets older, gunfire will not faze her.
Here is what I suggest: This method works nicely whether the dog is to be kept in the house or in a run Buy a couple of good size stainless steel pans to feed and water the dog from and then starting when the pup is first brought home, clang them together a few times a distance away from th pup, in the next room, for instance whenever it is feeding time. Make a racket and then immediately call the dog to eat so that it comes to associate the noise with feeding time, something she loves. Within a few weeks you should be able to start dropping the pans with the dog in the room at feeding time. At no time should you show any reaction to the noise in the dogs presence!
Gradually increase the amount of noise you are making with the pans until you are dropping together from head high. Again, call the dog immediately and feed her. Soon she will be running to you when she hears all th clatter.
Your dog will soon learn to love all of this commotion and this makes our next step very easy. I am hoping that by the time the dog is about 20 weeks of age you would’ve begun your new pup on obedience work. Once you are to the point where you can take pup somewhere out in the county where she can actually hunt a bit and encounter some birds (check your local game laws if you do this out of season or on state or federal property) or maybe lucky to have lots of wooded grassy area that you own, obtain a .22 blank pistol and take pup out in the field for a run.
You will need to watch your dog very closely for this next part as it comes in several steps and you must know if the dog is ready to move on. As the dog is hunting ahead of you (hopefully ahead!!) of you watch for an opportunity when the dog has flushed up a bird and is giving a good chase AWAY from you. With the dog in full run at least a couple hundred feet off, pop the blank pistol one time. The dog will likely look back at you upon hearing the report, and she may ignore you altogether. No matter what just keep walking along, SAY NOTHING to the dog and DO NOT react in any way to the shot. I would fire no more than TWICE on the first day just to be sure. If the dog is pointing and allowing you to flush her birds, be sure you allow her to chase the birds off quite a bit before you fire.
Once the dog seems fine with a blank pistol at a distance, gradually fire the pistol at closer ranges, being very careful to watch for any signs of concerns or discomfort on the part of the dog. If the dog shows any concern at any time, fire no more shots that day and increase the distance the next time out until she is ignoring the sound of the pistol. Remember it is important to fire only when she is chasing something, having a good time, so she will assocaiate gunfire with excitement of game. This is what we want her to come to live for and get excited over.
Once you get to the point where you can fire the pistol within about 10 yard of the dog with no trouble, repeat the whole process with a shotgun. I use my 12 ga. with light loads that I load myself some prefer to use a 20 ga to start but be careful about keeping 100 yard out from the dog shooting up and away from your dog. Again, the dog should not get any cues from you, fire the gun, say nothing and just keep walking. As long as the dog has no reason to believe the sound will hurt her, she will just accept the noise as part of what happens when she is hunting and will associate the sound with having fun. At this point you can incorporate this all very nicely as you start to work your new gun dog on her bird manners using liberated birds.
If you do this right and take your time, when it comes time to shoot hat first bird for your dog, there will be no problems or surprises and will have a dog that is convinced that gunfire is one of the Best things that there is. FUN FUN and more FUN for you and your new gun dog.