@Rarebear – thank you for bringing a note of reason into the guilt mongering of “would you be asking if it were a human.” I completely agree with you 13×7 = 91 and even if that is not completely accurate, 13 is a ripe old age. I have a 14 year old who did the same thing jumping off the bed. I opted to keep her as quiet as I could and give her pain pills as she seemed to need them. That was about 8 months ago and now she once again seems fine. She is however a small dog. Surgery is risky at any age, anesthesia is tricky, if it were my knee at that age, I would probably get myself a mobility scooter and terrify pedestrians.
The point that I haven’t seen brought up here is that I thought there was very little guarantee that surgery for ACL is going to be successful. Does anyone care to comment? Unless someone is going to give me very good odds that the recuperation period is not going to be more traumatic than the actual injury and that there will be a positive outcome from the surgery I would not consider it.
On the other hand I know of a woman who has a kelpie, not quite as old as yours, who had the surgery a couple of months ago and nearly drove herself crazy trying to keep the dog controlled during the recuperation, she ccrated it most of the time, anyhow the result is very good, the dog now seems to have no pain at all and is moving freely. But hey, so is my little dog.
So there you go, not much help, but I like to look at all sides of the picture. I don’t think it is going to get any worse by waiting so what do you have to lose? Treat her with pain killers, google holistic treatments for acl tears and use those suggestions, keep her quiet and see what happens in time. If she gets worse, you have your answer.