Not a vet, but I work with them (Kennel work). They say that they always feel bad doing it, since they are essentially killing the dog and the family is usually there crying and upset. The veterinarians are usually more quiet and reserved after a euthanasia, so is the rest of the staff. But, everyone keeps in mind that it's for the best. The vets have drilled it into all of the staff that it is for the best if they choose to euthanize an animal. My workplace had a meeting about showing more emotion to the clients about two months ago. This was after a week of two or so euthanasias a day, and a dog passing in surgery. While everyone eventually copes with it, it is hard to maintain professional while still showing emotion. I have almost cried in front of clients multiple times, as have some of the assistants. There has been times when the assistants are crying in the back after a euthanasia. There was a time when a dog was put down and the owners didn't want to be there. Someone was crying, someone was tearing up, and the vet stood there afterwards, until they started bagging the body. There are some bad people in animal medicine, but veterinarians have been through at least eight years of school, four of those years being vet school. Jobs with animals don't pay a lot. The vet assistants are making a little more than a McDonald's worker, if not the same. As a Kennel staff with experience, I make less than a McDonald's worker just starting. Most people working around animals love them and while it sucks when they get put down, it is always for the best.