TRUST -- the saddest poem I've ever written

I remember the first time, twelve years ago,
   when a spring-loaded kitten
      jumped down from my desk and sat on my lap.
His name was Shamus,
   but we sometimes called him "Wild Thing",
      so I was delighted to have earned a little trust.

Today, "Wild Thing" was sitting on my lap for the very last time,
    as we waited for the vet to open that dreaded door.
He was serene -- I was sad,
   but also delighted that he put all his trust in me.
I remember thinking how his life is truly in my hands,
     and how it troubles me to have already made a decision
         that he doesn't know about ...
 or does he?