Are the Bullenbeisser and Mexican Hairless Dog both dogs?
Bullenbeisser The Bullenbeisser (also known as the German Bulldog) was a breed of dog known for its strength and agility. The breed was closely related to the Bärenbeisser (some believe that the two breeds were the same; the names mean "bull-biter" and "bear-biter," respectively), and the Boxer. It was, in all its aspects, similar to the present Alano Español (Spanish Bulldog) and very alike to the Dogo Argentino, not only in aspect, but also in usage. There were two regional varieties, the Brabanter Bullenbeisser and the Danziger Bullenbeisser. The breed is now extinct.
Toy Bulldog The Toy Bulldog is an extinct dog breed that existed in England at 18th and early 19th centuries. Breeders were working in two different directions to create this breed. One was to downsize the Bulldog. This was not very successful due to complications with breeding sub-regular size dogs of this breed together. The dwarf size Bulldog puppies were and still are occasionally born out of regular size parents, but they were neither the healthiest, nor the most fertile dogs. They often produced regular-size puppies. Thus, this version of the breed had never been established.