As long as you can get her through acute attacks, you can probably manage the chronic symptoms for a long time. My Aunt had a mini schnauzer
that lived to be 19 years old with chronic panc. :-) As for testing, I'd probably just go by how the dog behaves and what symptoms are present. If she looks bad, she probably IS bad. After that, it's a matter of knowing when she needs hospitalization. If she can't keep down water for a couple days, she'll need IV support.