One of my friends recently had her second GSD (she had another, totally unrelated GSD with the same problem 4 years ago) diagnosed with this disorder, and now must give medication and carefully monitor feeding for the rest of the dog's life:
http://www.epi4dogs.com/
With some research, I read that this disease is seen more frequently in the GSD than other breeds. So, it made me wonder...has this disorder been seen in the CSV?