Hey...don't beat yourself. That stuff is SO common in the Northeast. Kudos to you for doing labs on him....lots of people short cut on vetting and don't have a clue their dog is sick until it is really bad. That is why I always do yearly labs on my pups...they are ofen the first sign that something is going on.
I have never heard that about it taking years off of their lives. I think once treated, he is going to be just fine!