So sorry to hear that Mike - it's really horrible when that happens. Old age/ illness/ combination of the two?
I had my cat put down a few months ago, and despite my best efforts, was in floods of tears at the vets.
Illness - chronic kidney failure. He was only eight. And yeah, I was in bits.
Sorry to hear
I'm not much of a "pet-person" but the little buggers get to you. My only experience was with a very sociable Budgie. Impossible not to break down when they have to go