He has a small cyst on his kidney, and very high blood pressure. His blood levels and the protein in his urine show chronic renal failure. Kidney disease. On the down side (it's some down side) there's no cure - dogs don't get transplants. On the upside, we have caught it very early, and first we will try some medication, then we'll try to get his blood pressure down, and maybe then we'll see a specialist to see if there's anything else to be done. We may change his diet. He's nine. He might live really well for years - a presumptive diagnosis isn't written in stone on a memorial tablet.
And yes, I feel rotten. But God is God, and I will praise Him; or, as Habakkuk puts it:
Though the fig tree does not bud
and there are no grapes on the vines,
though the olive crop fails
and the fields produce no food,
though there are no sheep in the pen
and no cattle in the stalls,
yet I will rejoice in the LORD,
I will be joyful in God my Saviour.