Sable or recessive red?

Sable is a pattern which can give anything from a dog that looks solid red to one that is heavily shaded. To be sable, the dog is required to have at least one copy of ay on the A-locus (gives sable pattern), as well as kk on the K-locus (allows expression of A-locus).
A recessive red dog is always clear red (or golden or cream) without a single eumelanin-tipped hair in the coat. This pattern requires a slightly different combination to appear - it needs ee on the E-locus (gives inability to express eumelanin in coat). It does not matter what it has on the A- or the K-locus.

Neither sable nor red is tied to any known health problems, but it can still be of interest to be able to tell them apart, especially when curious about what colours a combination may produce. But it can be hard to tell the two apart, as they can look similar. Here is an attempt at finding the trademarks for the respective colour.

Sable puppies

A sable puppy is born darker than it will be as an adult. They can be surprisingly dark in colour, often a dull grey-brown almost all over, with some darker shading. As they grow older, the coat with clear. In the adult, it can turn out to be a clear red with no trace of shading. The picture above illustrates a sable saint bernard puppy. Adult saint bernards often have dark shading to some degree, but it is normally found mostly on the upper body in the adults, rather than evenly all over as in this puppy.

Recessive red puppies

Recessive red/golden/cream puppies are never born with shading. Their coat will be solid red from the start - it may actually appear a shade or two ligther than it will in the adult! The labrador retriever above demonstrates how even the young puppy will have not a single black hair in its coat.
Comparing puppies is probably the eaisest way to tell if a dog is sable or recessive red, but it is possible to get an idea from the adults as well.

Adult sable dog

The adult sable dog can have no to heavy dark shading. If it has any visible dark shading anywhere, you can be certain it is a sable and not a recessive red. Likewise, if the dog has a dark mask on its muzzle, it is a sable. If the dog has only a little bit of light black tipping, it will usually be visible around the ears (not to be confused with darker cream shading in a cream dog).
Clear sable dogs with a mask is often referred to as 'fawn'. A 'regular' fawn has black pigment. You can also have a blue fawn, a liver fawn or an isabella fawn.
At first glance, it can be tempting to classify the american staffordshire terrier above as red, seeing how it was no visible shading. However, the black mask and black spots above the eyes give it away - this dog is genetically sable.

Adult recessive red dog

The adult recessive red dog may have lighter and darker shades in the coat. This labrador retriever may, at first, resemble a sable dog, with the darker ears, eyerims and lips. While recessive red dogs cannot produce eumelanin in the coat, it can still be present in the skin and nose/eye pigment. A close inspection of the dog will however reveal that he has not a single black hair anywhere in his coat. This means he is a recessive red.

In order to sum it up, when trying to decide whether a dog is sable or recessive red, look at the following:

• If available, study puppy photos. Sables are born darker, recessive reds are not.
• Sables often have some degree of darker tipping in the coat, especially around the ears. Recessive red dogs will have not a single black hair in the coat, while they can still have black lips and eyerims.
• If the dog has a black mask, it is a sable, as a recessive red dog would be unable to produce one.