Dogs eating poop is a common problem in any breed. If they eat their own, it is sometimes a learned behavior - they see you picking it up and think they are 'helping'. If they are eating other dogs' poop, they could be hungry, could be missing something in their diet, or again, exhibiting a learned behavior about picking it up.
Scolding a dog when they do it is a great way to break the habit though if they are fixated on it, they may continue doing it. Spraying with Bitter Apple is a great way to stop it as well. Picking it up 'immediately' is also a great way (though if they see you doing it, they may still repeat the behavior).
Knowing it is normal behavior though brings a sigh of relief (at least to us) - getting them to quit it is a bit more of a creative thing - but keep at it - it'll work! Check to make sure that they are not underweight though or have any other food problems such as allergies, etc. to cause it if the above solutions don't work.