
I know when looking to change my insurance provider as the one I was with won't insure a dog if you breed a litter from it. So was checking out the exclusions and all the ones I looked at didn't cover working dogs, they said things like they did not cover dogs used in the course of a business, working dogs, guard dogs, dogs trained to attack or dogs used for breeding, dog used for commercial breeding, gundogs, gundogs or dogs involded with shootings of any type.
Animal friends who I was with said 'gundogs or dogs involded with shootings of any type.' So I'd guess even done as a occasional hobby rather than an actual working dog would not be covered by then. So gundog owners who want to do that sort of thing and insure would need to check it's won't void there insurance.