What is Colour Dilution Alopecia, and does it affect Danes?

Colour Dilution Alopecia (CDA), also known as blue dog or blue Doberman syndrome, is a genetic condition that causes progressive hair loss (alopecia) due to an alteration in how hair pigment is formed and stored.

It is caused by inheriting two copies of the recessive MLPH (dilute) gene, resulting in a homozygous d/d genotype. This genetic makeup causes a defect in melanosomal transport within the cell, leading to melanin granules clumping together. These clumps create a defective pillar structure within the hair shaft, making the hair physically weak and prone to breaking easily.

Affected dogs usually show clinical signs early in life, such as sparsely furred ears and tails, which progress to hair loss on the trunk. Furthermore, dogs with CDA are highly prone to lifelong, recurrent secondary bacterial infections, such as folliculitis and bacterial furunculosis.

Does it affect Great Danes? No, CDA does not appear to affect Great Danes.

While Great Danes can absolutely inherit the d/d genotype—which is responsible for producing the recognized “blue” coat by diluting black pigment—the risk of actually developing CDA is breed-specific. Genetic tests can confirm if a dog has the dilute coat color, but they cannot predict if the dog will develop alopecia. Fortunately for the Great Dane, much like the German Weimaraner, the breed’s blue lines do not appear to be affected by the hair loss and skin infections associated with CDA, whereas breeds like Dobermans, French Bulldogs, and Labrador Retrievers are highly susceptible