A few years ago, all the Border Collies in a sheepdog trial would have been black and white or tricolor. Now, increasingly, there are red ones out there. The public is surprised: "I thought Border Collies were black!" and the old timers are scornful, or at least apologetic: "He was the last one in the litter; I couldn't help it." How do these red dogs happen, and why are there, apparently suddenly, so many more of them?
The red Border Collie, like the chestnut horse, is the result of a recessive gene pair. As you may remember, genes are always present in pairs, one inherited from the mother, one from the father. The two members of the pair may be alike, or they may be different. If they are different, one is expressed in the animal; this is the "dominant" member. The other member of the pair, the "recessive," is not evident in the animal itself, but may be passed on to later generations. If two of these recessives meet in an individual, their version of the trait will be expressed.
In the case of the dogs, the dominant (black) is called B, and the recessive (red) is called b. A black dog may be either BB or Bb; the red dog is always bb. Two black dogs may have red puppies if both of them are Bb; the b can come from each parent to produce bb in the pups. Statistically, one out of four pups from such a cross will be red. If either parent is BB, though, the combination can't produce red pups. If both parents are red, bb, then all their puppies will be red; there is no B available from either parent to make a black pup.
The end product of most genes is some sort of biochemical substance. In the red color, the chemical is a pigment called eumelanin. This is one of a group of pigments, the melanins, which cause color in animal skin, hair, and feathers. It is responsible for very dark brown or black color.
All Border Collies have in their hair a red version of melanin, called phaeomelanin. In the black dogs, the black eumelanin covers the appearance of the red. If you've ever looked closely at your black dog in bright light after he has spent a lot of time in the sun, you will see a faint red glow to his hair. The eumelanin has been bleached by the sun, and the red color is showing through, however slightly.
Only the dominant version of the color gene results in eumelanin production; if the dog has two copies of the recessive version, he will have no eumelanin. His hair will contain only the red pigment, and anywhere that he would otherwise have been black, he will instead be red. This means he may have the same variety of white markings as any black Border Collie; he may be tri-color, with lighter brown markings in all the usual places; he may even be a red merle instead of a blue merle. His nose and toe pads, which would be black on a black dog, are red-brown.
But why are there suddenly more of them? Probably partly because of the large influx of newcomers in Sheepdog trialling, people who haven't the prejudice against the red dogs that so many of the traditional Border Collie handlers have. These people aren't ashamed to come out to a trial with a red dog, and so we are seeing more of them in public.
More importantly, the red gene is present in some of our favorite breeding lines. The first recorded red Border Collie was a bitch named Wylie, grandmother of the famous Dickson's Hemp (153). The recessive gene passed through the generations to J. M. Wilson's Cap (3036) who appears in the pedigree of Wiston Cap at least 16 times! Wiston Cap carried the red gene and passed it to many of his sons and daughters. Our current Border Collies tend to have many crosses of Wiston Cap in their background; each one increases the chances of receiving that e gene. Crosses on both sides of the family, likewise, increase the chances of a double dose and the appearance of more and more red dogs. These dogs are beginning to convince even the traditionalist that a red dog can do the job.