Provided the dog hasn't already got its Stud Book Number (which it gets by winning certain awards) then you can add your affix on to the end of the name but the first part of the name stays the same. This is so in future if people look up records they are not confused by a dog with a different name. There is an exception to this, if you bred both of its parents you could then put your affix on the front. Years ago the breeder did not have to register the dog, the new owner could give it any name they liked, now breeders have to register each puppy. If you sell a dog to someone and they put their affix on the end, and you then get the dog back you can remove the other persons affix (unless it has a Stud Book number as above). Of course all these changes cost money!