Dachshund Coat Colours – DNA Testing
For anyone interested in the genetics of coat colour in Dachshunds, Healthgene.com have an explanation and can offer a range of DNA tests to determine what genes a Dachshund is carrying.
They say they can identify the presence of “true red”, black or black and tan or red with dark tips and chocolate or chocolate & tan coat colors, and black or brown nose in all six varieties. They go on to explain the genetics…
There are two “a” alleles at the agouti locus in Dachshunds (ay and at) which cause the two main underlying coat color patterns: sable and black-and-tan (or chocolate-and-tan). Note that color terminology in Dachshunds is a bit confusing in regard to sable and red. Sable is a reddish color with darker tips on some hairs. “Clear red” is a solid red with no hint of black tips on any hairs. However, Dachshund owners have often used these terms interchangeably. Each of these agouti colors may occur with or without dapple.
At the present time there is no DNA test for Dapple (or merle), but since the dapple 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 and eye defects are common.
White spotting also occurs in Dachshunds and no DNA test is yet available to predict this. It is often called piebald in Dachshunds and is inherited as a recessive.
Each of these agouti colors may also occur with or without brindle. Dachshunds that have at least one ay allele will be full-body brindles. 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. Dogs which are “ee” may carry brindle but would not express this pattern.
DNA testing for the “a” alleles in Dachshunds that are sable or black-and-tan (or chocolate-and-tan) 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. There are two common alleles in Dachshunds at the E locus: E and ,b>e. True red Dachshunds are “ee” and this genotype masks the expression of brindle and tan points.
Dachshunds have two alleles at the B locus: B and b. Dogs that are “bb” will have chocolate-and-tan coats if they are at at, but only their noses will be chocolate if they have an ay or are “ee”.
Note: a coat of intermingled red and black or brown hairs, called “boar”, also occurs in this breed. We have not had the opportunity to study this color and therefore carriers can not be distinguished at this time.