Coat colour saddle tan vs black-and-tan (RALY/ASIP marker) - Dog

What does this test examine?

This DNA test examines a RALY duplication marker on chromosome 24 that helps distinguish saddle tan from black-and-tan in dogs. It is most relevant in breeds where this marker-pattern relationship is well described, including the Basset Hound and Pembroke Welsh Corgi.

Saddle tan and black-and-tan are related coat patterns, but they create a different adult appearance. Black-and-tan dogs keep more sharply defined dark areas with tan points on the muzzle, eyebrows, chest, belly and legs. In saddle tan dogs, the dark pigment often recedes during growth, leaving a darker saddle on the back and larger lighter areas.

How does this fit coat-colour genetics?

The RALY marker lies close to ASIP, the A locus. The result should therefore be read as part of a wider coat-colour picture. The E locus, K locus and A locus strongly influence whether the pattern can be expressed visibly.

Inheritance and result

For this marker, the normal allele is shown as N and the duplication as dup. In the described breeds, N/N and N/dup are interpreted as saddle tan marker status, while dup/dup indicates black-and-tan marker status.

• N/N: saddle tan marker status; only N is passed on.
• N/dup: saddle tan marker status; either N or dup can be passed on.
• dup/dup: black-and-tan marker status; only dup is passed on.

Practical value of this test

This test helps breeders plan coat-colour expectations more accurately within relevant lines. It is useful when puppies are born black-and-tan but may develop a saddle tan pattern, or when breeders want to know which marker status a dog can pass to offspring.

• Helps distinguish saddle tan and black-and-tan genetically in suitable breeds.
• Supports mating choices when the adult pattern matters for breeding goals.
• Shows whether a dog can pass on the duplication.
• Adds useful context alongside A, E and K locus results, which together shape the visible pattern.