A reader writes:
Those bulldogs are a bad example of non-monogamous behavior. Try though they may, they are really being celibate. Breeders have made bulldogs so deformed that they rarely mate without human assistance, and they rarely give birth without C-sections. (They also have trouble breathing and are prone to many genetic diseases and disorders.) Here's some more info:
"Bulldogs in general are not able to mate naturally by themselves and it is common practice among Bulldog breeders to provide assistance to the bitch and the stud during matings by means of various methods and innovations. Novice breeders who want to do assisted matings with their own Bulldogs are advised to first get some practical experience with the help of an established breeder before trying it on their own."
"Selective breeding in the Bulldog for big heads and narrow hindquarters (pelvises), as prescribed by the Official Bulldog Standard, effectively means that Bulldog puppies with their big heads must pass through a narrow birth canal, which is the result of the bitch’s narrow hindquarters. To add to this potential birth hazard, Bulldog bitches in general tend to have inadequate uterus contraction, which is needed to expel puppies during the birth process. The combination of these factors is the reason why purebred Bulldog bitches can very seldom give birth naturally and requires that caesarians be done as a rule rather than an exception."