Puppies born after 06/04/07 will not be eligible to be shown where there is a fee paying public but this is quite amusing, as very few Shows charge - they get their revnue from the exhibitors and quite a few shows will not be happy at losing in the short term quite a considerable swathe of exhibitors. I know that new exhibitors will emerge and the breeds will continue, albeit with probably a slightly different breed standard. Many breeders - especially novice ones - will breed for a particular set, length and thickness of tail, to the detriment of other far more important considerations.
However, even Breed championship shows will still legally be able to accept entries from post 06/04/07 docked dogs, as they don't charge entrance fees and never have.
I doubt the KC will do anything to support traditionally docked working breeds (I don't agree with purely cosmetic and unnaturally short docks as per boxers, corgi etc) at their show, Crufts but it is pretty simply got around - they would just have the first hall filled with rings of those docked breeds, where the public can pass through on their way to the turnstiles where they do pay - ie, they choose to pay for the rest of the Show and gain access to all the commercial stands, ! Job done but, of course, it's controversial.
I am wondering if I could contest paying the full registration fee for each of my puppies, as they would be precluded from some of the KC's activities....
However, too much effort, methinks!!
