I love dogs and can certainly understand where you are Carlos. Ultimately you are going to have to make the call. My

since you asked is as follows based on owning dogs my entire life.
Think about the dog and what's best for him. The money aside, is going through this truly going to improve his remaining years or only make what time he has left harder on him?
We all want to keep them around for as long as we can and I am no different. But at some point we are doing it for us and not them. I have come to peace with it in my own mind, that in the later years of my dogs life I make them as comfortable as I can and hope nature takes it's course. Most times I'm not that lucky and have to end the pain and suffering via euthanasia. At the point my dog is only suffering is the point I make that call. I feel I owe it to them to send them on.
It has to be one of life's hardest decisions to make.
Prayers sent for the both of you.