I found several sites online about this topic, this one has a lot of straight forward info:
http://www.k911.biz/Petsafety/DogEatsPoop.htm
I watched the animal planet show "It's me or the dog" and the trainer on the show cut up pineapple and mixed in the dogs food, dogs apparently don't like pineapple the second time around and won't eat their poo.
Also canned pumpkin works.