Coat Colour D-Locus 1 – Dog

Affected animals (two alleles with mutation; d/d) have diluted coat and nose colour and the eye colour lightens to amber. Black dilutes into grey, also called blue or charcoal. The coat ranges from silver to almost black, but all homozygous dogs have a blue nose. Chocolate/brown/liver dilutes into lilac/light tan/Isabella, whilst their noses vary from pink, liver to isabella. Red/yellow/cream dilutes into champagne. Mutations in the D-locus can sometimes cause colour dilution alopecia, as the dilute coat colour is linked to hair loss (alopecia). The severity and occurrence of alopecia vary both within and between breeds, meaning only some dogs with d/d will develop hair loss and certain breeds are more prone to the condition. The variable presentation of this condition suggests that additional genetic or environmental factors contribute to its development. Affected dogs typically display hair loss between four months and two years of age, and their coats may appear dry and dull.