Even after eight years you're too close to it; you're thinking of your grief, not of the reader.  In grief, as in love, every detail is precious; for a narrative poem, most details are dispensable.  Hope this is useful:


Miles (after Miles Davis,)
had something wrong; his liver enzymes were shot.
So I left him at the vet to be examined 
while I went on a job interview.
When I get home the doctor's 
British accent was unexpected.  I'd expected.
It's some sort of infection,
here's a prescription, let him sleep.
Instead this: "There is a tumor and the x-rays 
show it wrapped around his liver. 
I can't biopsy because the shock. 
even under general, would kill him straightaway."
He had read Miles's death sentence.
He might as well be wearing a white wig.

I am a slow study but started to sob.
Said "I'm sorry - I promised myself
I wouldn't do that."
The vet didn't say "Man up" 
or "It's better," but let me cry 
then gather myself to arrange the time,
after hours, for the procedure.

I came to Miles with an Irish whistle,
played "Amazing Grace." He couldn't care less,.
annoyed by the IV feed
in the vein of his right rear leg 
he was trying to get out. I was just in the way.

When the the barbiturates pumped into him,
he toppled and died at once.
We were witnesses in an execution chamber.
I looked up.  Tears ran down the vet's face.
Months later I asked him, "Was I seeing things?" 
"I was crying," he said..
"It's not hard to do if the animal 
is old or terminal. But after an accident, 
abuse, or in a young one,
it's still very hard. I believe that Miles 
had life left in him but he had no choice."

I imagine Miles as one of my children, 
not seeing it coming: the brake failure,
the drive-by.  Years later I surrendered 
an old cat, who welcomed her release, 
but Miles was surprised by a terrible grace,
entry too soon into a world without pain.