Livernose – the charming variant of the Rhodesian Ridgeback
We quote Dipl. Ing. Agr. Walter Federspiel:
"The Genetics
The Rhodesian Ridgeback is bred from light wheaten to red wheaten. In most cases, it possesses black pigment (eumelanin). This causes the black nose, dark mask, and ears, as well as dark eyes, pigmented gums, black teats and claws, and a black violet patch. If a dog lacks black pigment, it is classified as a livernose, liver-nosed, or red-nosed Ridgeback. The lack of black pigment affects not only the nose, as the name might suggest, but all of the body parts described above. The entire color difference between black-nosed and liver-nosed is determined by a single gene. In the dominant (BB) and split-gene or heterozygous form (Bb), the dog is phenotypically black-nosed, although we cannot, or hardly, distinguish whether a dog is homozygous or split-gene. In the recessive form (bb), the Ridgeback has a liver nose. We're dealing here with a simple dominant-recessive and non-sex-linked inheritance pattern. The distribution between blacknosed and livenosed can be explained by Mendel's second law (the segregation rule). There are six different mating variants.
It should be noted that the calculated values only occur exactly with a very large number of offspring and can deviate considerably from the prognosis for individual litters. In the case of black-nosed dogs, we often do not know whether they are homozygous or split-nosed. The frequency of allele b (an allele is a possible expression of a gene, here b for livernosis) in the population can only be estimated; however, no concrete conclusions can be drawn from this with regard to a specific mating, but only for the entire population. A genetic test that clarifies this question is likely only a matter of time. The inheritance of the dilute gene (D = undiluted intense color; d = diluted non-intense coat color) occurs independently of B and has nothing to do with the occurrence of livernosed in the affected lines, as is often claimed. However, since the dilute gene affects practically only eumelanin (black pigment), liver-nosed dogs, in which eumelanin is lacking, cannot be identified with Dd and dd, and black-nosed dogs with Dd cannot be identified. Their status can be easily determined with a genetic test. Mixed nose (usually seasonal, with a brown-tinted nasal mirror) is a metabolic disorder whose cause is not conclusively understood; it occurs in many breeds. This disorder, too, certainly has nothing to do with the inheritance of B.
The exterior
The breeding goal is to produce a beautiful dog with a uniform brown color. The coat color, nose, eye color, and claw pigment should contrast as little as possible. Red-wheaten dogs appear particularly noble, while lighter-colored dogs often appear somewhat bland. The otherwise quite precise Rhodesian Ridgeback standard says little about livernose.
There are only two guidelines: The nose should be black or brown. The eye color should match the coat color. Showing a Livernose is a difficult matter; very few judges are able to correctly assess the specific characteristics of a Livernose. I have been with judges who didn't even know this variety existed. A Ridgeback specialist judge once frantically searched the entire dog for black pigment – naturally, she found none – and noted this as a fault. The biggest difficulty is usually judging the eye color. Judges from Anglo-Saxon and Scandinavian countries are usually somewhat more familiar with Livernose because it is more widespread there. Otherwise, the same requirements apply to red-nosed dogs as to black-nosed dogs. Many Livernose Ridgebacks are very elegant, lean, and light-bodied, with somewhat limited bone strength. The males are often large and have somewhat less substance in their lower jaw.
The breeding
Despite the small number of red-nosed dogs, inbreeding is not a major problem, as the entire population is available and is almost always mated with black-nosed partners. Livernoses also occasionally occur from unexpected pairings. Well-known males that have shaped the breed include Globe's Roving Red Regent, his son Khwezi Archenar, Bango Leoridge, and his sons Hassani, Ihlobo, and Inyanga, all of Ka-Ul-Li's Ridges. Tandiwe Merigal's Mad Gamble, imported by Elisabeth Pestalozzi, also left an impressive mark. Currently, two proven split-gene males are licensed for breeding in Switzerland: Merigal's Runako Tsavo, who is descended from Mad Gamble, and Makatso Junior of Ka-Ul-Li's Ridges. Dibaya Akilah's Peppe (Mashuri) may also be split-gene. His paternal grandmother is the well-known Livernose bitch Kisangani Red Ruby, and his maternal grandfather is Hasani of Ka-Ul-Li's Ridges. Amiri de la Brigadière, a grandson of Mad Gamble, could also be split-nosed, although there were no red-nosed puppies in the litter with Merigal's Paghera, a proven split-nosed bitch. Among the bitches licensed in Switzerland, the Livernose bitch Liwaza of Ka-Ul-Li's Ridges is in breeding. Merigal's Phalana and Paghera, as well as Mhondoro Faraa of Indian Fire, are definitely split-nosed. The Russian bitch Makena could be split-nosed, as could Baina Xarit d'Afrique, as both of her parents are split-nosed. This list is not exhaustive, but it does show that the frequency of b is quite high. Using Livernose dogs in breeding doesn't just make sense to breed red-nosed dogs, they can also significantly improve the color of black-nosed dogs. This is particularly effective in cases where the coat is too sooty or where many dogs are too dark, reducing the accumulation of black pigment (eumelanin) and clarifying the color. Unfortunately, there are currently very few Livernose males available for breeding in Europe. It is hoped that more Livernose Ridgebacks will be bred and shown at exhibitions in the near future, so that this noble variant of our beautiful breed becomes known to a wider audience. "
Published in the RRCS Club News in December 2010
About the author:
Walter Federspiel He holds a degree in agricultural engineering from the University of Applied Sciences specializing in animal breeding and nutrition. He has been keeping and breeding dogs for 30 years, including 13 years with Rhodesian Ridgebacks.