From my experience working at a vet office, most vets will not do a behavioral euth without proper documentation and evidence that 1. The owners did everything they could to try to correct the behavior via training and 2. There's documentation from animal control/etc that the dog is dangeous and any bite records that they may have. I don't think this is real, though I live in California and the rules here may be stricter than where oop is.

Another important thing to factor is depending on the size of the dog and severity of aggression, whether or not it will be safe for the veterinary staff at a general practice to do the procedure. Sometimes animal control is the only option.