Do you already have a pregnant Bully ? Was she health tested before she was bred..OFA, CERF, Baer, etc? Was the male tested for brucellosis? The dog's diet is very important, as she requires a lot more calories to feed the pups, and she must have enough calcium and folic acid. You need to feed her an excellent brand of dog food, preferably one containg very little or no grain. Do you have any experience with dogs whelping? How old is the dog? It would be nice to have a little more information about your dog to advise you.