I have a GSD too she is a puppy and she driving me nuts but she dosent eat her "#2" lol but i had another dog before that did and i corrected that by using a newspaper and every time you see her in the act get the newspaper or something that makes noise and shake it in front of his/her nose ( make sure you dont hit her ) I know a lot people may not agree with this method but it did work for me !!
Mine doesn't generally eat poop, but when we were in farm country he ate cow poop. MY friend's GSD eats horse's and sheep's it seems. I suppose it has something to do with them being herders.
I believe there's some truth in this. A lot of kibble dog food won't break down completely on the first pass through. Raw fed dogs, I think!, will be less likely to go back for a second helping.I "believe" it's due to left over nutrients in the feces.