Very sorry for your loss.
We're on Golden Retriever #6, over 38 years. Lindy Ruff was rescued from the SPCA 12/08. They said they thought he was 1yr. So if that's true he's 12+. Very slow on stair climbing now, but still very happy. I know the day is coming for him but it will still be very difficult. All pets are special but dogs form a special attachment. My wife says this is our last dog but I say day at a time. I've had a dog my whole life, and can't imagine not owning one, so we'll see.