Definitely! We are an old bastard retirement home here.
our woof clan has, at various times, consisted of a 9 year old boy. Sadly he was with us a year only and we nursed him through kidney failure in his last months. A still going strong 12 year old girl with one eye, who we've had 3 years. We brought our currently 9 year old boy home last year. He's a lazy fucker - he's utterly awesome.
My current old man had never had his own human before - he'd been kept outside in a builders yard. He didn't understand play. He didn't understand treats, or rolling over for belly rubs, or walking on lead. Old girl has taught him how to Dog - he chases after balls now. Doesn't grab them when he gets there, but at least he does just sit and watch any more. His favourite tv show is sitting and watching the oven, drooling. She's taught him to use a dog bed, and he's picking up lifting his paw when there's treats - although he falls over. A lot. It's awesome watching an old man like him learning to become a pet.
I'm not gonna lie - the amount we've paid in vet bills has been huge, but kidney failure, eye removal (well, surgery to correct the shite job of removing it), and general old man Labrador issues, could be experienced in a pup very easily
We've also had a young girl who died at under 3 years old, so getting a young dog is no guarantee of longevity.
I love my Old Git Army.