JOYBULL AUSTRALIAN & SOUTHERN CROSS BULLDOGS
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How to produce Liver Pigmentation in the Aussie Bulldog
P.O. Box 239, Miller NSW 2168, Australia
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Many people refer to a liver nosed as a “Dudley”.
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.
1.A nose that is entirely pink.
2.A dog that has a nose that is two colors of pigment also known as a "Dudley" and this can vary from very light flesh colored on a light yellow to a dark brown on a red or dark yellow.
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 order
- Dominant black to dominant black
- Dominant black to black with liver recessive
- Dominant black to liver
- Black with liver recessive to black with liver recessive
- Black with liver recessive to liver
- Liver to liver
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 B
B BB BB
B BB BB
Since both parents are liver,
all the puppies will be liver.
b b
b bb bb
b bb bb
Since both parents carry the
liver gene, approximately 50%
of the litter will carry the liver
gene and 50% will be liver
B b
b Bb bb
b b bb
Since both parents carry the liver
gene, approximately 25% of the
litter will be dominant black,
50% will carry the liver recessive,
and 25% will be liver.
B b
B BB Bb
b Bb bb
Since only one parent
carries The liver gene,
no liver puppies can result,
but all puppies will carry
the liver gene
B B
b Bb Bb
b Bb Bb
Since only one parent carries
the liver gene, no liver puppies
can result but approximately
50% of the litter will
carry the liver gene.
B B
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.