IMO, there should never be a shot around a pointer that doesn't have a bird in it. When I gun break a dog I will tether a BW or pigeon, and restrain the dog (Check cord) with the bird flapping in front of the dog, but dog just can't quite get it. Meanwhile I have another person shoot about 50 yards out and observe the dog, if it stays focused on the bird we move it in 10 Yards at a time, for me, this is a process I do not rush.
I just got through getting a rescue Brit from being gun scared, to at least gun tolerant, it was a slow Arduous process. Starting with a training blank, repeating with a shotgun only after I could shoot the blank gun on a just released bird and the dog did not take her attention off the bird during the shot. Knine also has a lot of good info on gun breaking, hopefully she will chime in.
Good Luck,
Gene