My buddy is blind and has had guide dogs for decades (labrador retrievers).
They typically retire around 7 or 8 yrs old. It’s always emotional for him.
There’s quite a difference between working dogs and pets. Working dogs are “on” pretty much all the time they’re not sleeping.
I've owned and been around bird dogs that do well till around ten or so, but their work is in spurts of a few hours during season.