This page is a very basic guide about how the different colour’s are produced. Firstly, please let me say that health temperament and soundness should always be given priority over colour when choosing breeding stock. Having interesting colours is just the icing on the cake.
First things first. I need to say that I am NOT a geneticist. I have had a lifelong interest in how different colours are produced in animals, and have spent a great deal of time studying books such as, The inheritance of coat colour in dogs, by Clarence C Little, and Genetics for dog breeders by Roy Robinson. Both very informative books, but even they cannot agree completely on just how some colours or coat patterns are created.
Coats can come in a whole range of colours, some are more common than others, and they can also come in a variety of different shades, depending on the modifying genes that can also be present. These modifying genes can be responsible for the size and density of the pigment granules in the hair, which is why you can get a range of, for example, brown coloured dogs, that can range from a very dark liver colour to a foxy red, they all have the same brown gene, but the density of colour is controlled by a modifying gene that gives the coat a different appearance, by altering the amount and size of the pigment granules present in each hair ( think of it as watering down the colour).
BLACK. Black is a dominant colour, it is normally shown as BB. or KK (There are ‘different forms’ of black, but we do not need to get into those here) Black can come in a variety of shades (remember the modifying genes?) some can be jet black, others can almost seem to have a brown tinge to the coat. A dog that is BB will not carry or produce any other colour, as it does not have the necessary recessive colour gene’s required.
BROWN. Sometimes called LIVER, CHOCOLATE or RED. This is a recessive colour. It is a recessive mutation of black, and is normally shown as bb. (Different shades are produced by the action of those modifying genes) Both parents have to carry the brown gene in order to produce a brown pup. A black dog that has one copy of the brown gene (that it can pass on) would be Bb (Black carrying brown)
A brown dog, has two copies of the recessive brown gene, so it can only pass on a brown gene, and would be bb. Brown dogs have inherited a copy of the recessive b gene from each parent, giving them two copies bb. In order to produce brown, both parents have to have at least one copy of the b (brown) gene, and pass that copy on to the pup. Each parent has to be either Bb – black carrying brown – or bb brown, it is not possible for two brown dogs to produce black pups, as brown is recessive to black.
BLUE Sometimes called SLATE or DILUTE, is produced by the effect of a dilution gene that dilutes the base colour. If the base colour is black, the result of this gene is to produce a blue (dark grey) colour, if the base colour is brown; the result is a diluted brown – milky tea- colour, sometimes called LILAC, FAWN or ISABELLA. shown as bb. dd = brown & dilute) It is normally shown as dd for dilute.
A dog that does not carry the gene for dilute would be shown as DD (non dilute) It is possible for any colour to be affected by the dilute gene. As with the brown gene, both parents have to carry the dilute gene, and pass it on to the puppy, in order to produce a dilute colour. If only one parent carries the colour and the other does not, you will not be able to produce a diluted colour, but a proportion of the pups will carry the dilution gene and be able to pass it on to future generations.
It is not possible to produce a non dilute (black for example) from two dilute (blue) parents. It is possible to produce a dilute (blue) from two black parents who both carry the dilute gene, or from one black and one blue so long as the black parent has one copy of the dilute gene, but if one parent does not carry the dilute gene, you will not produce dilute pups
SABLE. Sable is a little different, it is shown as ay, and in its pure form it has the effect of producing a yellow coat, this is sometimes called – clear sable -.
You are more likely to be familiar with shaded sable- this is a yellow coat, where the tips of the hairs are black. There is often a dorsal stripe of more darkly shaded hair and a mask of darker shading though this can vary in individuals considerably. Some sables can be so heavily shaded that they can almost appear to be tri, and saddle pattern sables where the head and legs are yellow but with a distinct black saddle, it is possible to get brown sables, where the tips of the hair and nose lip and eye pigment are brown and a dilute sable or blue sable where the hair tips and nose lip and eye pigment are blue/grey.
You can also get sable merles, but because of the paleness of the coat these can be hard to detect from normal sables once they get their adult coat. ( see Rio, he is sable merle) They are quite easy to distinguish as pups. Sable is recessive to most other colours with the exception of tri, it is dominant to tri. So in order to produce sable, both parents have to either be carrying sable, and/or tri.
Any colour can produce sable, if both parents carry the sable gene, or if one parent carries, or is, sable and the other parent carries, or is tri. It is not possible to produce sable pups from two tri parents
ee RED sometimes called RED, YELLOW or GOLD. This is the same gene that is found in yellow Labradors and golden retrievers, along with a number of other breeds.
It looks the same as a clear sable, and can vary from Gold to pale cream, there should be no other coloured hairs in the coat.
This gene has the effect of stripping the colour pigment out of the coat, a bit like if you washed your hair with peroxide most of the colour would be stripped out.
It is a recessive gene and needs to be passed on from both parents in order to show itself in the pup, if the original base colour is black the dog should have black nose/eye/lip pigment, and if the base colour is brown the nose/eye/lip pigment will be brown. If the base colour is a dilute then the body colour would be very pale with pigment to match.
People often ask if it is ‘safe’ to mate two ‘coloured’ dogs together. There is no hard evidence to suspect that such a mating is going to produce any more problems than mating two black and whites together. Look at other breeds, rough collies, shelties, corgi’s, GSD’s regularly breed sable to sable. Retrievers and Labradors breed ee dogs together, Weimaraner are all dilutes and Sussex spaniels are all brown, to name just a few, there is no reason to suggest that the repeated mating of coloured dogs together is likely to produce problems or weaken the colour. The only exception to this rule, is with the merle gene, see below.
Occasionally dilutes can exhibit a condition known as ‘Dilution Alopecia’ with very thin coats and hair loss, they can also show a white frosting around the edges of the ears, however this is not particularly common, and so long as both parents have good coats and no noticeable hair loss there should not be a problem. As with ALL colours, only fit healthy dogs with no obvious conditions that could be detrimental in any way should be bred from.
COAT PATTERNS. Coat patterns can be seen in any colour.
MERLE. Merle is a coat pattern, not a colour, the gene that produces the merle pattern, reduces the pigment in random areas of the coat. So a ‘blue merle’ is really a black and white dog that has had the pigment reduced in parts of its coat giving it the appearance of a blue/grey dog with black patches. If these random patches happen to be over the eye area you get blue or marbled eyes, or if on the nose, lips or eye rim, you get pink skin. As merle is a pattern, not a colour, it is possible to produce it in any colour.
You do however need to have one merle and one non-merle parent to produce the merle pattern. It is not possible to produce merle pups from two non merle parents. As the pigment reduction is random, and it can also have a tremendous amount of variation in the amount of pigment reduction you see.
It is possible to sometimes get, phantom merles. These are genetically merle dogs, that have just a tiny patch of merle hair, maybe only a few hairs, often in a place where it hardly notices. But as these individuals are genetically merle, they can still produce merle pups, with normal distribution of the merle pattern, giving rise to the belief that merles have been produced from two non merle parents. Mating a merle to an ee red/yellow is not a good idea, as due to the ee red gene removing all of the black pigment in the coat, it can be virtually impossible to detect which pups in the litter are actually genetically merle, and this could result in accidental merle to merle mating’s in the future.
TRI The typical Tri markings are also a coat pattern, and as with merle, it can be produced in any colour.
In order for the tri pattern to show itself, it has to have two copies of the tri gene, and to have received a copy of the tri gene from each of its parents.
In the case of tri, the gene responsible is a recessive gene; this simply means that If the pup receives two copies of the tri gene, one from each parent, you have a tri pup, If it receives one copy of the tri gene, and one copy of the non tri gene, you get a non tri pup that carries a single copy of the tri gene, and can pass the tri gene on to future generations.
If it receives two copies of the non tri gene then you have a non tri pup that does not carry tri and therefore cannot pass it on to future
I hope this gives you a little insight into how the different colours are produced, and if you find the subject as interesting as I do I hope it will encourage you to delve deeper into the more extensive articles that can be found on colour genetics to obtain an even better understanding of the subject.
I have been breeding coloured border collies now for well over 40 years, over the years I have managed to produce a lot of the colours seen in border collies, so my knowledge is based largely on experience, and study. In recent years I have also seen a number of ‘new’ colour variations, some attractive and some just plain odd. Ranging from pups that have the colours reversed (dark where you would expect light and light where you would expect dark) and a mixture of colours you would not expect to find on one dog. Which just goes to prove that nothing in colour breeding is ever ‘black and white’ and as the breed evolves we can expect to see more mutations, and variation, and possibly a whole rainbow of new colours popping up in the breed.
I am sure if you already have a good understanding of genetics, you will already understand the basic principles of colour inheritance, but for those of you who find all the technical jargon a bit mind blowing, I will try to explain it simply, in layman’s terms, just to give you some idea. If you want to get a deeper understanding there are plenty of sites around that can explain it all in more depth. There are new colour combinations popping up all the time, some of which are not even written about in detail in the genetic sites and books, but I will try to explain a little about the ones that are most often seen.
Every feature of your dog, from the length and colour of its hair, to the size of its ears, and the length of its tail is dependent on its genes. Genes always exist in pairs, and at the time of conception, the pup inherits one of each gene pair from each of its parents. (Otherwise, the total number would keep doubling up,) Each colour, or coat pattern has its own gene pair, that is responsible for its colour, as well as modifying genes that can alter the depth of colour, and it is possible for a dog to have the genes for a whole variety of colours, though you may not be able to see some of them, they can still be carried, and pop up in future generations.
Which of the gene pair it inherits from each parent in each case is random, which is why parents can produce pups of different colours in the same litter. Genes can be dominant or recessive. A recessive gene is a mutation of a dominant gene. The colour you see will depend on whether the pup has inherited the dominant or the recessive gene from each parent. Dominant genes are normally shown as capital letters, ( BB = black) while recessive genes are shown in small letters. (bb = brown) It is possible for parents that are both a dominant colour to produce pups of a recessive colour, but it is not possible for two recessive coloured parents to produce a dominant colour pup.