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Nederlandse versie English version Coat colours in dogs What are 'coat colours'? In dogs, as in most mammals, the pigmentary colours of coat and skin are very limited. There is melanin in two forms: eumelanin that brings about the colours black and brown (chocolate, liver) and phaeomelanin producing colours between reddish (mahogany) and yellowish brown. Then, responsible for the colour of the red blood cells, there is haemoglobin that causes the pinkish colour of mucous membranes and of the non-melanin parts of the skin. There are many pairs of genes (at least ten, probably more) involved in how and where both kinds of melanin are produced. Apart from these there are several pairs of genes that determine the length and the structure of hair and coat. All together they cause the phenotypic expression we call 'the colour' of our dog. At this moment DNA tests are only available for a limited number of coat colour alleles. The presence or absence of eumelanin in the coat is regulated by the E-locus. Animals with at least one dominant E-allele (EE- or Ee-animals) show a 'normal' development of eumelanin in their coat. The meaning of the word normal here is: 'as determined by the other colour genes'. Animals that are homozygous for the recessive restriction allele (ee-animals) do not produce eumelanin in their coat. Their coat will be 'reddish', a colour between mahogany red (like in the Irish Setter) and yellow (as we know from the Labrador Retriever and many other breeds). The eumelanin pigmentation of the skin, as we can see in the eyes (including the eyelids) and the nose, is not affected by the e-allele. There is a third allele in the E-series; it is the allele Em that restricts the production of eumelanin to the facial mask (a colour pattern we see in many Molosser breeds). The colour of the eumelanin in the coat and in the skin is determined by the B-locus. Animals with at least one dominant allele (BB- or Bb-animals) will produce black eumelanin, the ones that are homozygous for the recessive allele (bb-animals) will have brown eumelanin in their coat and skin. Other colour genes determine where and how much (black or brown) eumelanin is produced. DNA tests for coat colours Breeds that can be tested Breeding policy Testing for coat colours