I can’t answer that but I would ike to use this discussion to say that I’m generally impressed by veterinarians. They have patients that are actually different species and (e.g. in dogs) their size and weight varies widely. They can’t speak or consent to anything and they often actively hide if they’re in pain or impaired. Placebo effect probably doesn’t really work either.At the same time the owners (if it’s a pet) often love them like a child and get super worried and / or pissed if something happens.

Also regularly performing euthanasia (without the patients consent) probably is pretty though on their psyche.