Mastiffs and bulldogs each have a variety of breeds within their respective types. They share a number of physical characteristics, such as adorable, wrinkly faces and stout bodies, and they share a number of similar behaviors, quirks and places in history. Enough physical and behavioral differences exist, though, to easily distinguish the bulldog from the mastiff at a glance.
English History
The English mastiff, also known simply as the mastiff, gained the attention and respect of Julius Caesar in 55 B.C., when the courageous dogs fought alongside British soldiers as they battled the Romans. The mastiff has been bred in England as a guard dog for more than 2,000 years, but cave drawings depicting mastiffs have been found in Egypt, dating back to 3,000 B.C. Impressed by the mastiff's courage, Caesar returned to Rome with a group of them and forced them into bull baiting and lion fighting.
Similarly, the bulldog was also used in bull baiting in England. A descendant of the Asiatic mastiff, the bulldog was given his name partly because of his bull-fighting abilities and partly because his stout, wide body resembled that of a little bull. In later times, the mastiff was used by English peasants to protect the home and guard against predators. The bulldog also has a strong guarding instinct.
Using Their Heads
Both the mastiff and the bulldog have wrinkled faces. The mastiff has a large, square head with a muzzle that measures roughly half the length of his skull. He has dark brown or hazel eyes surrounded by a black mask and a scissors bite or underbite, yet his teeth do not show when his mouth is closed. The mastiff has loose facial skin that falls in folds around his eyes. The bulldog has a broad head with a flat, pug face -- a look some refer to as push-faced. He looks like his face has been pushed flat against his skull. He usually has a pronounced underbite, many times revealing his lower teeth even when his mouth is closed. Excessive folds of loose skin fall around his eyes, and his upper lips hang well below his jawline.
Body Building
The mastiff, a massive dog, is one of the largest breeds recognized by the American Kennel Club. His sturdy body stands at least 30 inches high at the shoulder, or at least 27.5 inches high in females. Males generally weigh about 160 pounds but can reach more than 200. Females typically weigh about 150 pounds. The mastiff's legs are proportionate to his body size.
The bulldog, also sturdily built, reaches only 12 inches to 16 inches at the shoulder. Female bulldogs weigh between 49 and 51 pounds, while males generally weigh in between 53 and 55 pounds. The bulldog's legs are short, keeping him low to the ground and giving him a rolling gait. In the show ring, shorter legs are more desirable on the bulldog.
A Coat of Many Colors
The mastiff has a short, flat coat in solid colors such as golden fawn, light fawn or apricot. Brindle coats are also acceptable, according to the mastiff breed standard. The bulldog has more variety in his coloring, including shades of brindle, solid white, solid red, yellow, fawn, fallow, piebald or any combination of these colors.