It would be better than what we have and no different to a Fishing or shotgun licence.
You think so??, then it'll be, how many dogs do you keep, what breed, gender, purpose for keeping them, then you'll get the annual or twice yearly kennell visits (like the hunt kennels get now), any signs of work on them or, in their eyes, "cruelty", and you'll be hanging from the nearest yardarm mate.
Once you sign up to something like that you are accountable, and accountabillity for fishing, there's nothing to prove, you either catch and release or eat the fuckers, for what working dog men do y