Oh gosh, I'm so very sorry.
I have always loved German Shepherds. My current one is 4 years old, a long haired one.
My soul dog, Vic, was also a German Shepherd. Lost him at the age of 10 years old. To that tumor they tend to have growing next to their stomach. It ruptured.
They have so many genetic issues, its sad. Lot of cancers, too.
I always said I would be composed during the final good bye. For the dogs sake.
Instead I completely and utterly fell apart into a million pieces. I can't even talk about it much.
I'm so sorry. I can't even find the right words, but my thoughts are with you and your son.