prong

I have recently noticed some small, round bald spots on Jaeger's neck area. I suspect they are fur loss from his prong collar. Has anyone else experienced this with their dog? I've resorted to loosening the prong collar for now but I would like a different alternative that would prevent further...

I'm looking for advice on transitioning to a flat collar. Maeve has done prong and e collar training. We just enrolled in therapy dog classes. I know I can't test with anything but flat. Should I keep ecollar on and clip to flat and work her that way? Or go just with flat? She obeys well...