I empathize with you about Giz, what a blow for you. However, I can tell you that my Artful Dodger was diagnosed with hypertrophic cardiomyopathy when he was 9 years old and lived, on medication, to 16. If he hadn't developed both CRF and hyperthyroidism in the last year of his life, he'd probably still be with me. Hopefully, you are both going through the hardest part of this right now - finding out, having tests done (I was terrified during Dodger's since he had to be sedated), but then you should be able to put him on medication and enjoy the rest of the years you have together.

I'm hoping for the best for both of you.