Allowing unlicensed vet assistants to perform any kind of invasive procedure should be considered negligence.  Vet Techs spend years of studies and training and they should have clear differentiators from vet assistants who have no medical training.  I would NEVER take my animals to a vet who chooses a greater profit over the welfare of the animals they treat.  Besides, do vets not realized that if they have unlicensed vet assistants perform potentially risky procedures the insurance analysts aren't ready to pounce on raising insurance rates?