Hi, all. This is my first post. I got my first sheltie, Demi, when an ex-boyfriend showed up at my home and said "Take this dog or I'm taking her to the shelter." Demi went to heaven last month after 13 wonderful years and a very short illness. I'm starting the search for a sheltie puppy. And wow -- there's so much to consider!! In the course of my search, I got a lead on a litter of puppies. All merles because .... Daddy is a double-merle. This concerns me for two reasons: Why would a breeder even have a dm in the first place? He either created one on purpose, or created one by accident (either scenario shakes my confidence in the breeder). Or, maybe he "rescued" one which would be laudable, but you certainly wouldn't breed a rescued dog, right? I guess I'm just a little disturbed that the breeder has a dm. Are descendants of a dm, or merles in general, more prone to health problems? Please let me know your thoughts! Since I didn't "choose" Demi, I'm learning this stuff for the first time!