We have the same problem here. I am concerned. Our puppy, we have the mommy too, has one ear up and one down. It has been this way for a few weeks now. I thought about taping them. I am afraid the mommy will chew the tape off but I may have to keep them separated. They like to restle with each other. I am beginning to wonder if the mommy did damage to it. I don't know. Her one ear that stays up, went down over the weekend and I shaved them and trimmed them again and it went back up. But that one ear is just flopped over. I may try taping it and see what happens. The mommy's ears are just fine, both up and always have been since we got her. I was also wondering exactly how to tape them. I guess I can give it a try. Thanks for this question and to those of you who answered.