Could be wrong, but I always thought the "bulldog" referred to the pit bulldog, or American Staffordshire Terrier. Some strains of the breed are quite large, and used for fighting. A lot more active than the real bulldog. They were raised at Ft. Riley in Kansas where my father trained at the Cavalry School in 1918 approx. He brought one from there for me when I was born a few years later so that it could be "raised with me" as a protector. It was large, with a neck like a defensive lineman.