My dog was eating her poo too...and someone recommmended to me to put meat tenderizer on her food...It is the powdered meat tenderizer that you can buy in the spice aisle at the grocery store...anyway..i sprinkle a little bit on her food (it is just basically salt)..and the smell when they poo makes them not go near it...it has worked for my dog! Good luck!
Sometimes meat tenderizer works, and sometimes it doesn't. Much depends on exactly how much the individual dog really LOVES to eat feces. Some dogs never get over their fascination with it.
Don't forget to keep up with basic daily maintenance and remove those dog piles as soon as they're made. If it's not there, the dog can't eat it.
Nobody really knows exactly why dogs behave this way, but many theories are out there. Sometimes changing a dog's food or adding vitamin supplements helps too. Some dogs don't eat their own poo or even other dogs', but are attracted to cat feces. Cat food has a lot more protein in it, and there is still a lot left in their waste.
When one of our puppies developed this issue, it turned out that she was attracted to something in her puppy food formulation. When she was 14 months old and went to regular adult dog food, she stopped. Now we just have to keep an eye out for the houses with cats when we go on walks. Believe me, she can spot a cat pile half a block away. I know her body language well enough to know when she's ready to risk a dash off the sidewalk to grab a quick bite. :-D