10 week old puppy seizures

[Sher49]

I had a beautiful 10 week old puppy for 11 days. He was very active, no signs at all of any illness. He was put to bed Tuesday evening at midnight. I heard him crying and barking at 1:30 am. Once I saw him I realized he was having a seizure. I took him immediately to an emergency vet center. They couldn't stop the seizures without giving him general anesthesia. The xrays showed nothing. I picked him up in the morning to take him to my regular vet --he was so drugged he was out of it. My regular vet checked him out. He kept having seizures. He had to be put under general anesthesia again. She told me that her "unofficial" diagnosis is Distemper. He had his first distemper shot at 8 weeks and was going to get his second next week. I had to make the tough decision of putting this beautiful puppy to sleep as the vet said there wasn't any hope at all for him. Has anyone ever heard of a perfectly fine puppy one minute with no distemper symptoms at all -- then dying from seizures? I just really don't understand how this could have happened.