What kind of dog is in the picture of a little boy and a dog?

Bulldog (English name: Bulldog) is an animal of Canidae, a subspecies of domestic dogs, which originated in England and in19th century. Before 1835, it was a very common breed in England. There are French bulldogs, American bulldogs and other types. Bulldog is the mascot of many schools, organizations and even countries. For example, the mascot of Yale University is a bulldog named Shuaidan, and the United States Marine Corps and Britain also use the bulldog as the mascot. The bulldog is also the mascot of the bulldog team at Butler University in Indiana, USA. Since then, after selective cultivation, the character has gradually become elegant. The big head of the puppy may get stuck in the birth canal, so the bitch often has a caesarean section. One of the most effective breeds of dogs.