The term “Dudley” dates back to 1877 to a bulldog named Lord Dudley, who had a liver-colored pigmentation of the nose and lips. The “fault” was not outlawed at the time, and the dog was much used as a stud, transmitting this unique look, which became known as a "Dudley" or a "Dudley nose", to his offspring. However, the origins of this “Dudley” nose referred to a bulldog with liver pigment.
Chocolate/liver - bb gene Recessive
"B" - Dominant B (Black) - The dominant gene (B) directs the color of eumelanin produced to be black. This direction includes the black color seen on the body, masks, ears, brindle stripes, etc. Pigmented skin areas (like the nose leather, lips, and eye rims) are black.
"bb" - Recessive "bb" (Brown) - The recessive gene (bb) directs the color of eumelanin produced to be a chocolate brown but does not take the final step in eumelanin production of changing brown to black. Phaeomelanin (yellow/red) isn't affected. The pigment granules produced by "bb" are smaller, rounder in shape, and appear lighter than pigment granules in "B" dogs. Pigmented skin areas (like the nose leather, lips and eye rims) are brown, not black. Also, the iris of the eye is lightened.
BB .... indicates dog is dominant black; i.e., does not carry the liver recessive
Bb .... indicates dog is black nose but carries the liver recessive
bb .... indicates the dog is a liver nose
The gene for the liver nose is recessive - which means that both the sire and the dam have to carry the gene in orderfor them to produce liver nose puppies. I am using the term «liver», which can also mean «red» or «brown».
Here are a few examples how liver is produced and how it can be recessive:
Since neither parent
carries the liver gene, no
liver puppies can result
B BB BB
B BB BB
Is the liver Pigment a genetic fault??
No this is just a fallacy. Its only a color it doesn't affect the health of the dog. If your dog has genetic fault than it would have it regardless of the color of its nose. You need to look at the generations behind your dog and see how it has been bred. If breeders are breeding soley for color than yes these lines could be more predisposed to health issues. Do your research. Ask what health testing are they doing ? Are they line breeding lines and doubling up on genetic faults? Blame the breeder not the color of the dogs nose. The only reason its not desired in the British Bulldog world cause years ago if they bred a Dudly nose it indicated a line that wasn't pure.