It's important to understand that:
* Dogs do not typically eat their own feces unless there are underlying medical or psychological issues.
* Wartime conditions were incredibly stressful for both humans and animals, but there's no reason to believe this would cause a dog to engage in such behavior.
This claim is likely a misunderstanding or a fabricated story.
If you're interested in learning more about German Shepherd dogs in wartime, I recommend searching for reliable sources like historical books, articles, and documentaries.