My german shepard every so often eats her own excretion, she is 14 months old, how can I cure her of this?

If it was me I would get some jelly crystals that keep dogs away, dogs hate the smell. (I can't remember the name of them, ask the pet shop)

After your dog does its excretion, put the product (crystals) around theexcretion.

Give the dog ample tome to explore its now undesirable terd (excretion).
Repeat the procedure over and over

I haven't heard of the jelly crystals but if you sprinkle them around the poop after the dog has defecated then wouldn't it make more sense just to pick it up?

I have heard that adding meat tenderizer or pineapple to their food can help deter them from eating it, but then again, it's hard to get a dog to eat food with pineapple in it!

What sort of toys does she have and how much exercise does she get daily?
Also what brand of food are you currently feeding?

There are measures to train her not to eat her stools such as cleaning up as soon as she goes to the bathroom. You can also add crushed pineapple or a little bit of meat tenderizer to her food to make it less appetizing.

I would be concerned that using a deterrent such as the gel crystals might send the message that you don't want her to use that area to potty.

An interesting article/overview (the authors are doing a study) about Coprophagia (eating feces), it's causes, and some 'treatments':
Douglas Island Veterinary Service - Coprophagia (http://home.gci.net/~divs/behavior/coprophagia.html)

I have to say that the meat tenderizer on the food works very well. I have never been able to get my dogs to eat pineapple though :(

Eating feces is, unfortunately, a natural dog behavior. They all do it at some point in time. The only time you want to start getting worried is when it turns into a habit.

All those additives work great. But the one and only cure-all that DOES work 100% is to pick up after the dog.

If the yard gets dirty, or her favorite potty area is full of poo, then she's going to start cleaning up. When this type of behavior turns into a habit (eats poo anytime of the day, or even other dogs poo) that when you want to start adding things to food or making it a point to follow her with your poo pick up tool.

I run a rescue along with my mom. We have lots of dogs, and during a certain period of the year (typically fall going into winter) they all graze in their own feces. That is the only time that every single dog in our kennels will eat their poo. The behavior leaves just as quick as it appears.

Good luck

My dogs seem to have a liking for cow patties. Gag me. But your right, the 100% cure all is to pick it right after they poop. I know sometimes it isn't possible, that's when those other tricks come in hand.