Actually, I had a rottweiler for a short time, when I had my 3 shelties. It was funny because I had 2 shelties, then my daughter wanted the rottweiler and we got her, then we got the 3rd sheltie puppy. The 2 older shelties were snotty to the rottweiler and the new sheltie puppy, but the rottweiler was older than the puppy, and she took care of the new sheltie puppy. I was very careful to be sure the rottweiler's whole family was at the breeders and they were all gentle and gave kisses. Only problem was that I was disabled and the rottweiler was pretty stupid. I could not house break her, or even train her to get off the couch. It took me and my foster-daughter to drag her off the couch (we'd lay there catching our breath and she would be back on the couch before we were). I found a good home for her with another rottweiler in a some fenced acreage. If the two of you could handle a rottweiler, it could be very good for your sheltie. That rottweiler was sooo gentle with the sheltie pup.