German Shepherd with a sick stomach

[norm258]

My GSD, Hunter, started vomiting last night. This is the second time where he goes for about 18 to 24 hours vomiting regardless of what goes in him - water, or anything else.

He seems to be settling now and I will introduce some light food with some yogourt later today if he's good all day.

I read that someone mentioned "shepherd stomach" in one of the posts - can someone explain what this means? I know GSD's have sensitive digestive systems but not really sure to what extent. To fill him out some, I fed him Pedigree for 3 months, and now using Iams Probiotic large breed. I struggle to get him to eat most of the time though. We have tried mixing wet canned meat, gravy, drippings, whatever we can find and some times it doesn't even work. Has anyone found a way to keep dogs really interested in their food? Perhaps another brand of food? Suggestions are welcome!

Thanks in advance.
Norm