I'm sorry too. :-(
That's the problem with pets. We always out live them.
Our cat (well, not really OUR cat - she adopted us!) was hurt somehow - probably hit by a scooter or car about three weeks ago...
The owner never put a collar on her, so we put a flea collar on her and used a permanent marker and wrote our apartment number on the collar. Well, three weeks ago, there was a note on our door, that someone found her in the bushes, and she was injured, and at the vet, so we called the vet and learned her hind end was paralyzed. :-( We had to put her down. :-(
I am sorry to talk about my friend in your time of grief, other than to say, you're not alone. :-(