For AKC purposes it is possible that the multiple-sired litter will in fact be recorded as multiple litters whelped by one bitch at the same time. The solid principle is that our registry accurately records the sire and dam of each dog registered. Multiple-sired litters are in accord with that principal. If you had told me ten years ago that I would support the registration of the multiple-sired litter, I would have said you were crazy. That was ten years ago.
Today is today.