I cannot lie by your fire

I've changed my ways a little, I cannot now
Run with you in the evenings along the shore,
Except in a kind of dream; and you, if you dream a moment
You see me there.
So leave awhile the paw-marks on the front door
Where I used to scratch to go out or in,
And you'd soon open; leave on the kitchen floor
The marks of my drinking-pan.