Gestation is 59 to 63 days usually though can be a little sooner or later. Most Bully's tend to go on day 60 or 61. Bulldog breeder's keep track of when their dog was bred and count the days carefully and begin taking the temperature at the appropriate time so they know when to head in for their c-section. It is rarely possible for a Bully to whelp naturally and on those occasions they tend to gut the pups trying to do the umbilical cords because of their bites. The breed also does not usually make good mommy's at first and all interactions must be closely supervised. They tend to lay on the puppies and smother them.