“Is that a Rottweiler?”
No, not a Rottweiler, Doberman or Dachshund! Just an incredibly well-bred Labrador retriever with beautiful coloring. And most importantly – a dog that will enable freedom for someone to achieve life’s goals.
Black and tan coloring in Labrador Retrievers is due to a recessive gene that each parent must contribute. When both parents have contributed the gene, the pup has lighter tan colored fur above the eyes, around the muzzle, on the chest and legs.
Another gene found in Labradors causes tan speckling on the legs and muzzle; this is called brindle. Black and tan and brindle Labradors can be registered with the American Kennel Club, but they cannot compete in the show ring as these colors are considered undesirable to the breed standard.
The Guiding Eyes breeding colony has been derived in part from the Whygin Labs, a prominent kennel that was very successful with show and hunting dogs in the 1970s. Some of the black and gene coloring stems from the Whygin line.
Because we breed for exceptional guide dogs, our primary criteria are temperament and health, not color. These pups have the same temperament and health traits as their solid-colored littermates.
Black, chocolate and yellow Labrador coloring are the result of the interaction of two genes commonly referred to as the E (yellow) gene and the B (brown) gene.
A dog with ee (two recessive copies of the yellow gene) is yellow. The B gene is turned off. This turning off or hiding the expression of another gene is called epistasis.
For dogs with Ee or EE, the B gene is turned on. A black dog results from BB or Bb. A chocolate dog results from bb.
Another gene present in all Labs is the K gene, which has several variations. KB is responsible for solid coloring, as we see in nearly all Labradors. The most recessive version of K is ky; two copies of ky will allow another gene, A (agouti,) to express itself in a number of patterns commonly seen in other breeds, such as tan points.
A single copy of KB is epistatic to, or sufficient to hide, all the genetic information of the A gene. Nearly every Labrador retriever has two copies of KB. In a small sampling of 200 random Labradors, about 4% were found to have only a single copy of KB.
When two such dogs are bred to one another, the probability is that 25% of the pups will inherit the non-KB version from each parent. Any of these dogs that are not yellow (ee) will have tan points.