Only dog that you can't train to hunt is a dead dog. If the dog is a house pet then he will be easier to train and be more responsive since he feels closer to the family. I would start with some basic training (i.e. heel, whoa and come) (which by the way if he responds to these commands 80% of the time you can hunt behind him) then I would introduce him to birds in a controlled environment. Watch and see how he responds. If he goes after the bird then let him go after it, if he shys away or is cautious about it then give him time. Stop for the day and do it again the next day. After a few days he will get courageous. Seen it many times. Once he decides he wants the birds then you can work with him. On the issue of "gun shy" never ever ever just shoot a gun around him just "too see if he is gun shy." That is one sure way to make a dog "gun shy." Here is what I do and I have never had a gun shy dog. First be loud around your dog. Clap your hands and talk loud (I'm not saying to scream, just talk loud.) Then start banging a pot with a spoon or something. I usually do this around feed time. At first he may be cautious and shy but keep it up, but be easy with him. When he will approach you without shyness then you can move on. Next I have a cap gun. When he is out running I will fire one cap and see how he does. If he is good then will fire another. Don't fire too many keep it simple. Once he and you are comfortable you can let him get closer and fire cap gun. Then step up to a 22 blank gun (just FYI, you can get 22 blanks at Homedepot for nail guns alot cheaper than at gundog stores) and work with him out in the field. Once he shows no interest then go to shotgun. Remember, start small and work up. Never start firing "next" to dog. That way if he flinches you can back off without harming the situation. It takes time and is not a "over night" deal. Once he is where you can shoot over him and he has basic training down and shows "birdiness" then go hunting. Everything else is gravy.