While I agree with this to some extent, vets can report you to the rspca if you refuse to let a vet put your animal down. I read a case about an elderly man who was advised to put his dog to sleep. He told the vet he needed to take his dog home to process this info' and say his good-byes.
After a few days the rspca turned up. He was prosecuted for allowing his dog to suffer unnecessarily.
Do You Have Any Strange Memories?

