Cocker Sable (eH) | Coats and Colors

The e^H allele at the E-Locus causes an interesting phenotype in Cocker Spaniels that either resembles a regular sable pattern or is described as a dirty red color pattern. A version of domino similar to e^A or e^G in other breeds actually causes both of these phenotypes.

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What is Cocker Sable?

The e^H variant found at the E-Locus modifies any background coat color pattern by partially inhibiting eumelanin production. It causes a pattern to have way less eumelanin than expected.

To give you an example, this puppy should be solid black:

The effect is very similar to northern domino (e^A) and sighthound domino (e^G). However, cocker sable (e^H) has a much stronger impact on a pattern compared to the other domino alleles.

English Cocker Spaniels are fixed for tan points (a^t/a^t), they don’t come with a real sable pattern (k^y/k^y A^y/-)^[2]. But in dominant black dogs (K^B/-), the e^H variant causes a very sable-like phenotype.

Hence the breed term “sable“, found only in Cocker Spaniels.

Cocker Sable is expressed as a sable-like pattern on dominant black dogs with a hidden tan point genotype (K^B/- a^t/a^t). These dogs should be solid eumelanic in all their pigmented areas.

But their domino variant (e^H/- K^B/- a^t/a^t) causes a modified A-Locus pattern.

Cocker domino decreases the amount of eumelanin in the coat while promoting pale hair roots and drastically extending any tan areas in the pattern.

On dogs that would normally express their tan point pattern (e^H/- k^y/k^y a^t/a^t), the domino variant causes a phenotype with residual black shading on a mostly red coat, known as dirty red.

Cocker Spaniel domino is considered an old but very rare coloration. The mutation behind this pattern is unique to Cocker Spaniels and seems to have been in the breed for about 100 years. However, most breed clubs consider sable a non-standard color, only some breeders try to keep this color alive.

The e^H allele

Pigment cells have the ability to synthesize either eumelanin or phaeomelanin. The E-Locus is part of the pigment type switch system that causes pigment cells to produce one pigment type or the other.

Cocker sable is caused by the e^H variant (officially e^H(D84N) or e^Hypostatic). This allele reduces eumelanin expression and produces more phaeomelanin than expected in any given background pattern.

e^H is recessive to melanistic mask (E^m) and wild type (E), but dominant over recessive red (e). Its relationship to ancient domino alleles (e^A) or grizzle domino (e^G) hasn’t been identified yet.

Since it shows a stronger eumelanin-reducing effect, I will put it closer to e than to E:

E^m > E > e^A ? e^G ? e^H > e

Masked (E^m) or normal (E) patterned dogs can be carriers of the sable trait (E^m/e^H, E/e^H). But all Cocker Spaniels that express a sable or dirty red pattern are e^H/e^H or e^H/e.

Some companies offer testing for the e^H variant. But there are no scientific studies and hardly any information that describes the mode of inheritance and expression of sable patterns in Cocker Spaniels.

Update 2024: The study on the e^H variant‘s ability to produce partial recessive red phenotypes has been published! You can find the study here.

E^h domino patterns

The e^H variant causes a partially inhibited eumelanin production.

It can modify any coat pattern a Cocker Spaniel would normally have.

Most Cocker Spaniels are fixed for a tan point genotype at the A-Locus (a^t/a^t).

So all Cocker domino phenotypes concern the effect on what should be tan points (e^H/- k^y/k^y a^t/a^t) or a dominant black dog with a hidden tan point genotype (e^H/– K^B/- a^t/a^t)^[1].

In theory, there could be even more domino patterns in Cocker Spaniels.

Recessive black (a/a) occurs in both English Cocker Spaniel and American Cocker Spaniel and even regular sable (A^y) occurs at a very, very low frequency in American Cocker Spaniels^[2].

Cocker Sable

Dominant black dogs with tan point genotype at the A-Locus (e^H/– K^B/- a^t/a^t) express a pattern that resembles a shaded sable pattern.

Affected dogs express a mostly cream- or tan-colored face with dark pigment on their forehead, ears, neck, and back. Some face markings like a widow’s peak or a darker nose bar are very common.

Sable also gives more phaeomelanin pigment on the dog’s legs and belly^[3].

Unlike domino patterns found in other breeds, e^H does not appear to lighten phaeomelanin color quite as much. Many sable-colored Cocker Spaniels exhibit a fairly normal golden pigment color.

A Cocker sable pattern may be partially hidden by piebald spotting, with some dogs expressing ticking and roan (aka sable roan).

Dirty Red

Tan point patterns can be modified by e^H to express as a light red coat with darker hair tips.

This is known as “dirty red” in Cocker Spaniel breeds.

Again, the e^Hvariant removes lots of the eumelanin from the original pattern.

The synthesis of eumelanin can be reduced to such an extent that it gives a “golden sable” phenotype, which may almost resemble a recessive red coat color.