When I spoke with the vet she said that the stones were too large to pass on their own or with food changes. She would need surgery. She is a medium sized dog. I had 2 others that died at 13 and 14. She seems fine, she is not in any pain right now but runs the risk of the stones causing a blockage although she doesn't have one currently. They cause bladder infections the last few months which we treated with antibiotics, but they came back I think due to the stones. She acts fine right now like she feels fine, no pain no constant urinating or anything. I'm tempted to wait since it doesn't seem to be bothering her but then I feel guilty that I am not spending the money to fix what can be fixed and I am responsible. Although there is no way to be sure she won't get them again. I have never had a dog that had bladder stones before. I will ask the vet the questions you suggested on Monday but I have a feeling they will tell me they don't know the life expectancy with or without the surgery. Bladder stones could kill her but if it won't for another couple of years is it worth risking the surgey?
What is the life expectancy with the surgery verses without, the vet must have some educated estimate. Also ask how long the dog will live without surgery and what can be done to manage pain or other problems that develop without surgery.
If you dog is a large dog it's normal life span may be no more than 12 year or so.
Then there is the question of love, but the above practical considerations are the same for us humans. In fact the extension of human live no mater what it costs or for now long the extension is, is though to be the main reason Medicare is going bankrupt. We spend hundreds of thousands on people who may not gain more than a year or two, and maybe at the additional cost of a very poor quality of life. I am a senior myself, so I'm not speaking about others when it comes to managing the cost of medicine.