This from Wiki, under "veterinary ethics" (excerpt):
..."The veterinary profession remains largely self-regulating across the world (e.g., by the RCVS and AVMA). This has caused some controversy as to why the veterinary profession remains one of the few remaining self-regulating professions.[1] Bernard Rollin wrote on this the difficulty in keeping public confidence while remaining self-regulating, trust and impartiality are critical but most importantly is the need for a profession to self-sacrificial by putting the clients needs above that of the profession or professional’s need.
“Every profession—be it medicine, law, or agriculture—is given freedom by the social ethic to pursue its aims. In return, society basically says to professions it does not understand well enough to regulate, “You regulate yourselves the way we would regulate you if we understood what you do, which we don’t. But we will know if you don’t self-regulate properly and then we will [hammer you with draconian rules and] regulate you, despite our lack of understanding.”[2]