How do I get my terrier/sheltie puppy to stop eating poop?

I have a 5 month old terrier/sheltie puppy. He's very smart, housebroken and taking obedience classes. The problem is he likes to eat poop. He started with his own poop. Now he's got a taste for cat poop and horse poop. He gets fed the required amount of food plus treats daily so he shouldn't be hungry. How do I get him stop?

Dogs have a master instinct to eat poop. There is no way to stop him other than keep him away from poop. Don't worry. It doesn't mean that hes any more stupid. DOGS LOVE POOP

Crazy as it sounds, I have heard (on Animal Planet) that if you feed a dog pineapple that it makes the taste of the poop horrible. Maybe it would work.. Good Luck!

I’ve read several articles on this. It seems to be more common than we’d really like to think. I’ve read that it’s a very common thing for puppies to do for several different reasons. Most often people will say they have a deficiency, which I’ve read isn’t true. I’ve read that puppies eat their poop because they have to taste everything … or for fear of punishment … or because they saw another dog do it … or maybe because it’s closes to what they got to eat from their mother … or because they're copying what their mother did to keep their kennel clean … but here are some links with more information on why and how to break them of that habit.There’s also a couple of links to products that can be sprinkled on their food to make their poop have a terrible taste. I don't exactly know about horse poop though ...http://www.hsus.org/pets/pet_care/our_pets_for_life_program/cat_behavior_tip_sheets/eating_strange_objects_such_as_feces.htmlhttp://www.drsfostersmith.com/pic/article.cfm?dept_id=&aid=748http://www.drsfostersmith.com/pic/article.cfm?aid=77http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=583http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=595

Dogs eat their poop because some of it contains food that is not digested. This is because dogs eat fast and don't chew all of their food. They smell the food in the poop and decide that its food.If you want to stop your dog from eating its poop, simply sprinkle meat tenderizer on its food. That will make its poop not smell so appealing to it.