A veterinarian I once worked with sent me several pictures along with a short explanation for each, and I gotta say, some of them are pretty bad (gory).
Here is an X-ray of an old, stray dachshund who was attacked by a rottweiler (BDLDLDL). Apparently the couple who found it wanted to ‘put it out of its misery’ by means of suffocation, but a police officer who was also at the scene decided to take the poor thing to the veterinary hospital so the euthanasia could be humanely conducted.
So, my question to you is: would it have been more or less humane to euthanise the dachshund on site (e.g. by either suffocating or shooting it) as opposed to protracting its suffering by taking it to the vet to allow professionals to euthanise the animal in a widely accepted fashion (i.e. via intravenous injection)?