Blue and Tan Dog Genetics: Doberman, Yorkie, Dachshund & More

Blue and tan is one of the most striking coat colours in dogs — a slate-grey or steel-blue body with warm tan markings. Here is the genetics behind how it is produced.

The blue-and-tan pattern is a combination of two independent genetic factors: the tan point pattern (A locus) and the dilute gene (D locus). Understanding both is essential for any breeder working with blue-coloured dogs.

The Two Genetic Components

Component 1: Tan Point (at at — A Locus)

As covered in the tan point guide, the at/at genotype produces the dark body + tan point marking pattern. On its own, with a black base, this produces black and tan.

Component 2: Dilute Gene (dd — D Locus)

The dilute gene (d allele) at the MLPH (melanophilin) gene locus reduces both black and red pigment:

• Black → Blue (grey-blue, slate, steel blue)
• Chocolate/liver → Isabella/lilac (pale dusty grey-brown)
• Red/tan → Cream/light fawn

When a black-and-tan dog (at/at) carries two copies of the dilute gene (dd), the black becomes blue-grey and the tan lightens to cream-tan. The result: blue and tan.

Genotype for blue and tan: at/at, dd (plus no dominant black KB, no recessive red ee that would mask the pattern)

Blue and Tan in Specific Breeds

Doberman Pinscher

Dobermans come in four AKC-recognised colours:

• Black and rust (Bb or BB, at/at, DD or Dd)
• Red and rust (bb, at/at, DD or Dd) — chocolate + tan point
• Blue and rust (Bb or BB, at/at, dd) — black diluted to blue
• Isabella (Fawn) and rust (bb, at/at, dd) — chocolate diluted to isabella

Blue Dobermans have a blue-grey coat with lighter tan points. Colour Dilution Alopecia (CDA) is significantly more common in dilute Dobermans — a progressive hair loss condition affecting blue and fawn dogs. Not all dilute Dobermans develop CDA, but the risk is elevated.

Yorkshire Terrier

Yorkies are characteristically steel-blue and gold (tan). The steel blue is produced by the dilute gene acting on the black saddle. A Yorkie's typical adult coat is: blue (dilute black) on the back/saddle and gold (tan) on the head, chest, and legs.

Young Yorkies are born black and tan and develop their blue colouring over 1–3 years as the coat matures.

Dachshund

Blue and tan is one of the accepted Dachshund colour combinations. The dilute gene dilutes the black to blue-grey, producing the blue and tan pattern with the same tan point distribution as the black and tan.

Australian Shepherd and Border Collie

Blue and tan Aussies and Borders exist but are less common than merle versions. The blue dilution interacts with the already complex colour genetics of herding breeds.

Colour Dilution Alopecia (CDA) in Blue Dogs

CDA is a skin condition associated with the dilute gene. Affected dogs develop:

• Progressive hair loss, typically starting on the back
• Dry, scaly skin in affected areas
• Secondary skin infections

CDA does not appear at birth — it develops between 6 months and 3 years. Not all dd dogs develop CDA, but the risk is higher than in non-dilute dogs.

There is no DNA test to predict which individual dilute dogs will develop CDA. The best management is selecting against lines with high CDA rates and informing buyers of the risk.

Breeding for Blue and Tan

To produce blue-and-tan offspring, both parents must contribute one or more dilute allele copies, and both must contribute at least one at allele:

Example: Black and tan Doberman (at/at, Dd) × blue and tan Doberman (at/at, dd) = 50% blue and tan (dd), 50% black and tan (Dd)

Example: Black and tan (at/at, Dd) × black and tan (at/at, Dd) = 25% blue and tan (dd), 50% black and tan (Dd), 25% black and tan (DD)

Summary

Blue and tan is produced by the combination of tan point (at/at at the A locus) and dilute (dd at the D locus). The dilute gene lightens black to blue and tan to cream-tan. CDA is an associated risk in dilute dogs — not universal but elevated. DNA testing at the A locus and D locus confirms genotype and predicts breeding outcomes.