This rather undesirable behavior can be normal in puppies. Young dogs often go through a stage of exploration and as part of this put lots of different things in their mouths to chew. Puppies simply love to chew everything! And sometimes this can include things that are even less desirable than your shoes!
There is also some evidence that the high levels of dexycholic acid in feces may help with their neurological development, however a balanced diet will completely eliminate any dietary need for feces. The most important tip for puppies exhibiting this behavior, is not to punish the act, but rather offer alternative things to chew and play with.
Positive reinforcement of good behaviours always sticks with your dog better than punishment of the bad. This has been proven in many dog behavioural studies. Punishment (either for eating feces, or doing feces in the wrong place) can also confuse dogs into thinking they actually need to ‘hide’ the feces – and you guessed it, the best way to do this is to eat it!
There can be a few other reasons for coprophagia, such as simple boredom or the fact your dog likes the taste. Addressing the boredom with regular exercise, toys, digging pits and lots of affection can sometimes solve the problem. It can also be due to behavior problems such as attention seeking behavior, a rare compulsive disorder condition or generalised anxiety.
Medical problems such as anemia, malnutrition or malabsorption, endocrine disease and bowel conditions are rare causea of coprophagia, and usually your dog will be perfectly healthy. Dietary deficiency is another rare cause and most commercial pet foods are balanced for the needs of your pet.
Dogs that are on medications that can increase appetitie can also lead to the problem of coprophagia.
Always ensure your dog is wormed regularly both to avoid the problem starting and to treat GI parasitism that can result from regular coprophagia.