Sorry to hear that man. I have a friend who is a vet tech. and she sees this too often. Her own vet just amputated his own dobermans leg at a much older age. I asked how the dog was doing and she said "great, a little depressed for the first 1-2 weeks, but is doing much better now". Just like people, everyone/dog is unique but I hear from a pretty good source they are resilient. Good luck to you family at this tough time.
"One foot in the grave, one foot on the pedal, I was born a rebel" Petty