Hello, My sheltie has had terrible ear mattes to the point the groomer had to shave them down to the skin. I'm trying to stay on top of it and leave his collar off when home so that the hair can fill back in. She suggested to get a round or rolled leather collar to prevent further matting. I have read there is a difference between the round and rolled and the round is better for the dog, maybe because of seams, can't remember the reasoning why. I'm sure either a round or rolled would be a good option to help prevent mattes, but my concern is my dog is very leash reactive. When on walks he lunges and barks to get to dogs walking the opposite direction. I realize this is a whole different post in itself and I have been trying many things to fix this behavior. I have better control of him with a collar as opposed to a harness when this does happen. My concern is will a round or rolled collar cause more pressure to the trachea than a flat collar when he pulls because the pressure is not evenly distributed as it would with a flat collar? Does anyone have experience with this as I'm sure there must be other leash reactive shelties out there that pull and lung to get to other dogs? Would like some feedback about the different collars for preventing mattes as well as not hurting a leash reactive dog.