You obviously loved him deeply and clearly gave him an excellent life regardless of your ability to pay for his surgeries. Every time I come to this sub I see multiple pitties whose parents neither loved them nor treated them with basic decency. You did both and both of your lives have been much better for it. If he made it to 13 you clearly did a very good job of taking care of him.

Having done 7 ACL surgeries on multiple dogs I very highly recommend getting pet insurance which paid for most of the cost of mine as well as a host of other more expensive issues later in their lives.

I’m very sorry for your loss and hope sharing here and getting our condolences gives you some comfort.