The issues is - how do you ban something that has no definition. The breed has AFAIK no official definition. There is no DNA test that can be carried out etc.
I think pretty-much it's a case of if it looks like a duck and quacks like a duck.... If people seemed to know well enough what they are when breeding, selling and buying, then am sure they can be recognised after the legislation change.
Definitions are difficult.
If there's a breed/type of dog where there is evidence of increased levels of harm to humans or other dogs that is over and above that other breeds/types of dogs we should be asking whether we want people to be able to own them in the first place, and if they do, consider leads and muzzles in public. One has to question why people wish to own such beasts as XL Bully's etc in the first place?
There's a young and 'uncontrollable' Rottweiler around here (owned by what seem to be sensible and decent kind of people) that is always walked on a lead but without a muzzle. Recently it had a go at one of mine who was off-lead at the time. It's a powerful beast that they can only just restrain. If for whatever reason they were caught off-guard, he could do a lot of damage and to my mind should be muzzled for the safety of others.
Dogs are wild animals at the end of the day, whilst we domesticate and train, there's always an element of unpredictability...couple that with an ability to kill or maim, owning such dogs is a risk and comes with extra responsibilities to minimise that risk.
