I am so sorry to hear about your poor guy's suffering. Its very difficult to let go and deciding the right time. It sounds like that time is here. I think the only thing you can do is give him as much love and comfort as possible. My thoughts are with you during this difficult time.
At the Bridge, running free..
Brando GSD 2/14/94 -6/17/03 RIP
Julietta GSD 4/4/03 -11/23/13 RIP
Rest in peace my babies.