Almost every dog I've ever had has had a taste for I guess what they think are the more delicate things in life....other dogs poop, their own poop and even more fun...the cat's poop out of the cat litter box! I would just keep them from doing it when you're with them, otherwise I wouldn't fret over it. Its a dog thing. If its their own poop they eat mostly you can sprinkle a product called "Forbid" on their food and its supposed to make their poop well....lol, less desirable! If they are on a good heartworm preventative you shouldn't have to worry about them picking up intestinal worms because most heartworm preventatives are also intestinal dewormers as well.
I too had this problem with my pup. I was told to add some pineapple to his food and that when it gets digested, the pineapple releases an enzyme that tastes horrible. Well I believe it worked! He no longer does it and hasn't since. My pup is only 5 lbs and only eats 1/2 cup of dry food a day, so I would put 3 tablespoons of canned, diced pineapple in his food. It was great because he also really liked the taste.