Presence of black, "clear red", chocolate and sable colors, and mask. There are two a alleles at the agouti locus in Cardigan Welsh Corgi (ay and at) which cause the two main underlying coat color patterns: sable-and-white and tricolor. Note that color terminology in Corgis is a bit confusing. Sable and red and fawn are different terms for dogs of the same agouti genotype. Other modifiers genes cause the difference in the tone of red or the relative amount of black hairs in the red coat. Although Cardigans are often called "black", solid black or black and white are not colors in this breed. The Cardigans called black are all tricolor dogs with black on the dorsal area and white on the ventral area, and a bit of tan in between. Each of these agouti colors may occur with or without Merle. At the present time there is no DNA test for merle, but since the merle pattern is exhibited by the Mm heterozygotes, the phenotype is predictive of the genotype. Note that MM dogs are primarily white and conscientious breeders avoid producing such dogs since deafness is typical and eye defects are also common. Each of these agouti colors may also occur with or without brindle. Corgis that have at least one ay allele will be brindle over most of the body, except on the white ventral surfaces. Dogs that are at at will have brindle only on their "points", i.e. they will be brindle where they would otherwise have had tan. At the present time, DNA testing is not yet available to detect the brindle allele. DNA testing for the "a" alleles in Cardigan Welsh Corgis that are sable or tricolor allows breeders to better predict the colors of pups from particular matings. Although some breeders believe they can "see" the difference between a homozygous and heterozygous fawn, this has not been reliable. Brown occasionally occurs in Cardigans, which is due to a bb genotype at the B locus. DNA test results will also report the genotype at the B locus. There are two common alleles in Cardigans at the E locus: EM and E. Dogs with any combination of these alleles may be brindle. It is possible that the e allele occurs occasionally, although thus far it has not be found in this breed. Dogs that are ee can carry brindle and not have any black striping since they are not able to produce black or brown pigment. Note that the melanistic mask allele Em is dominant, but since many Cardigans have white on their muzzle, the black mask does not always show phenotypically. |