My brothers mother in law raises Rotts and she has lost several at or around the age of 10 and mostly from some form of cancer. Mine had sudden paralysis in his back legs and I suspect a spinal tumor after talking to my brother who is a Veterinarian. I had to put him down at age 10 or 11 (cant recall exactly).
Oh, man ... sorry to hear that.
You know, this makes a really good argument for just going to the pound and getting a Heinz57. None of my GSDs have made it more than 12 years or so, most of them have passed much sooner -- and all of them to genetic conditions prevalent in purebred GSDs.
Duke, the Boxer -- he was 7, I think, when he fell over in the front yard while we were playing "go get it". Sudden cardiac arrest. Didn't know it was a prevalent genetic condition in boxers until I did some research on the internet that night. Poor guy ... I'd have done CPR on him but he didn't even have any reflexive response at all and his pupils were blown in the time it took me to run across the yard after he collapsed. He died a happy dog, though. That little nubby tail was going 900 mph when he left us.
Gotta take the bad with the good, I guess, but I'll freely admit it gets harder and harder as I get older and older. Maybe because I appreciate what a good dog brings to my life. And that is so much more than I am ever able to give them in return.