Our vet came to our house to put down our 11 year old Weimeraner. It was a horrible time for us but our vet made it bearable. She was able to stay in favorite chair and I think she was very comfortable. We live in a rural area so vet house calls are not unusual.
Ours was awesome. He scheduled us for the last appointment of the day and didn't have them come back into the exam room. He was gentle and didn't rush us at all. Dogs were nervous going in (they always were at the vet) but he was able to calm them down and it was a peaceful (albeit sucky) transition.
"Hello babies. Welcome to Earth. It's hot in the summer and cold in the winter. It's round and wet and crowded. On the outside, babies, you've got a hundred years here. There's only one rule that I know of, babies-"God damn it, you've got to be kind.”