My 15 year old cat had a stroke. He couldn't stand up on his own, kept falling over to one side.
We set him up with some towels in a storage bucket and I told my wife "I have to go to work, if he's not any better, we'll take him to the vet and have him put down."
When I got home from work, I looked in the bucket and said his name. He raised his head, put his paws on the edge and stood completely up, like "Goddamn it, I HEARD what you said."
He lived another 7 months.
At the end, all he wanted was to be warm so I made him a fire.