My vet won't euthanize our kitten?

We have a kitten and we were going to give her away to a pet store but then we noticed something was protruding out of his bum so we went to the vet and he told us that the cat's rectum has come out and turned inside out so he needed surgery which costs around 400 to 500 dollars. We chose to euthanize the kitten since we are not keeping the kitten. The vet then said it can't euthanize our kitten because he says it's not his choice to euthanize it, he has to call the council or ranger or something like that to come and inspect the kitten and house. Why is it not our choice? And why must a ranger, inspector or the council must be called for a kitten to be euthanized?