Originally, American bulldogs were farm utility dogs who could stand up to a bull, round up feral pigs and protect personal property. These breeding lines were known as classic and standard bulldogs, also known by the breeders' last names. To the untrained eye, there may be little difference between the Scott and Johnson lines of American bulldogs, but subtle traits make them readily discernible.
Origin of the Lines
Johnson bred two American bulldog bitches to an English bulldog in the 1970s to start the classic line. Breeding subsequent generations of pups created the line of stockier dogs with necks nearly as big as their heads. The Scott line was bred for greater agility and athleticism. Both came from the line of Old Southern Whites, the original line of American bulldog. Also known as White English, these dogs are still sometimes used to introduce fresh genetics to other bulldog lines such as the Johnson and Scott lines.
The Classic Johnson
Both are primarily white, although the Scott line is usually pure white while the Johnson has patches of red, brown or black. The Johnson most closely resembles a bull mastiff, with a wider and stockier body than a Scott. He has larger bones and his legs extend out to the sides of his body reminiscent of his English bulldog ancestors. He also has facial wrinkles with an undershot jaw and pendulous lips. The stocky build means Johnsons may weigh 120 pounds or more.
Scotts Have Their Standards
The Scott line of American bulldog is reminiscent of an oversized white pit bull. Scotts have longer legs positioned under their body instead of out to the side. He has a longer muzzle and either a level bite or slightly undershot jaw. His neck is arched and not quite as wide as his head, with a sleek, muscular appearance. Scotts have a strong urge to chase prey and are sometimes aggressive toward other dogs. Socialize a Scott as a young pup if dog parks or other pets are in your plans.
But Wait, There's More
Johnsons and Scotts aren't the only two subtypes of bulldogs, although those are the two distinct phenotypes. Over the years, breeders created additional distinctions. The Painter/Margentina type was a smaller version of the bulldog -- averaging about 55 pounds -- used for dog fighting. The hybrid bulldog combines the best characteristics of the Scott and Johnson, with a large, powerful head and neck balanced on a straight-legged athletic body. The Old Southern Whites from which Scott and Johnsons descended are still found in the deep South today.