Author © Tord Lundborg, Kennel Line Sam,
Can a mating between two black parents result in red puppies? I've seen a whole litter of puppies by two black & white parents being registered as blue roans. Is that possible? How can one tell whether a puppy is roan or open marked? How come that no puppy by a chocolate roan dog and out of a an orange roan bitch has neither of the parents colours but three others? In this article I will try to answer these questions and explain why a mating between two black & white Cockers cannot result in blue puppies.
My description of the inheritance of colours is based upon "Spanielboken" written by Marianne Hermelin. It's an old book, from the 50's I believe, which I just found in the library. This article has been published in Cockertidningen 4/95.
Some colour genes
are inherited in a predominant way. If the dog has this gene it will show. Other
genes are inherited in a recessive way. If this recessive gene is to be
noticeable, there must be no dominant gene hiding it. Dominant genes are
indicated with capital letters, recessive with small. The following indications
are used in Cocker Spaniels:
In the following examples I will simplify and just use the letters which are interesting in every specific case. The outcome in every table of division is theoretical and not applicable in every litter but in a statistically large enough selection.
The easiest case is when to solid black dogs without any recessive genes are mated to each other. Both of them will only carry black EE and all progeny will be black. Even if one of the parents carries red, Ee, the whole litter will be black. This is what it
looks like in a division table:
If a great number of puppies were born, 50% would be black without being carriers for red, EE. 50% would also be black but would be carriers for red, Ee. In this exact way PRA is inherited. If one of the parents is a carrier for PRA but the other is not, 50% of the puppies will theoretically pass on the disease, but none of them will get PRA. We won't know which is a carrier until we have the misfortune of mating it to another carrier with some puppies getting PRA as a result.
Two black parents can get red progeny if both of them carry red. They will then have E = gene for black and e = gene for red. In the division table it looks like this:
You can see that the chance of getting red puppies is 1 to 4, those in the table having the indication ee. Again, we can compare with the inheritance of PRA. Let's say that e symbolises the PRA gene, this means that ee will develop PRA, Ee is a carrier but will not develop PRA. EE does not even have a recessive gene and therefore will not pass it on.
Black & white Cockers can have these set of genes; EEttrr or Eettrr (carrier for red, e, which in parti coloured Cockers is called orange). If anyone of them had the roan gene, R, they would not be open marked but roan as R is dominant over r. The set of genes could be split into Etr and etr. In a vast number of puppies 1/4 would be black & white not carrying for orange & white, EEttrr, 2/4 would also be black & white but carrying for orange & white, Eettrr. Finally 1/4 of the puppies can be orange & white, eettrr. As you can see an orange & white dog has no dominant genes. That is one of the reason that this colour is rare.
How can one tell whether a puppy is roan or open marked? Orange roan and orange & white are often, but not always, born white as snow, with no visible spots. It might take two - three weeks before one can see light tea coloured spots on the puppies. Just after a few days the puppies start to get pigment on their noses and on the pads. If the pigment comes at random, then the puppy is open marked. It is the same with black & white. But if the pigment starts shaped as a dark ring around the pads and nose and gradually fills the pad towards the middle, then the puppy is roan. Blue roan puppies often already have pigmented pads and nose at birth. When the puppies grow older some open marked can show separate hairs of the blotched colour in the white parts, not as much as roan. This is called "Ticked". Judges often call these "light blue roan". Genetically they are open marked. Have a look at the pads. Open marked Cockers can still once they are adults have unpigmented parts of the pads. That does not happen in roans. Nowadays it is not unusual that we mate solids to parti-colours. In that way the basis of breeding is increased and that is not a bad idea. The negative consequences we see is that some puppies may be born with more white on the chest than is permitted by the standard. They can also get white hairs on the muzzle or on top of the head. In those places there must be no white if it is a solid Cocker. But those who are born with it do not suffer from the spots.
In this example a black & white dog is mated to a red bitch. He has the set of genes, EEttrr. I know that the bitch has the set eeTt because she is red and does not have a dominant gene for black, E, and her dam - Line Sam Gleam īn Glory - is black & white which makes her a carrier for parti colours. I believe that even the pure solid bred dogs can carry for roan or open marks. This is based upon the fact that this very combination resulted in roan puppies. The sire and grand dam does not have the roan gene and therefore it has to come from the solid red maternal grand sire, Greentree Donīt Think Twice. Half of the puppies will theoretically be solid black and the other half parti-coloured. The black puppies carry parti-colour, t. The parti-coloured could be either roan or have open marks. All puppies will be carriers for orange/red from the dam, e.In this combination was Cocker of the Year 1994 Line Sam Vikings thinks twice born.
In the last example a brown roan dog carrying for tan is mated with an orange roan bitch, who also carries for tan. His set of genes could be bbEEttRrCcII and hers BBeettRrCcIi. In reality this bitch had seven puppies: three blue roan & tans, three blue roans and one black & white. There are so many possible combinations that I prefer to split it into two different tables, one for the colour and another for the tan.
The colour table looks like this:
Theoretically there is only 25% chance of getting an open marked puppy, BbEerr. All puppies will get a black dominant gene, E, from the dog. This gene is a part of his brown gene, bbEE. It hides the red/orange gene, BBee, from the bitch and no puppy will be orange, i.e. the colour of the dam. In her orange gene there are BB. BB is dominant and hides the bb from the sire. No puppy will be brown roan but all puppies will be carriers for orange and brown.
The tan markings are indicated with a recessive pair of genes making the tan markings appear, cc, and the actual tan gene which is dominant, II. Let us suppose that the dog has the set CcII and the bitch CcIi.
Theoretically there is only a 2/8 chance of getting tan marked puppies according to this example, ccII and ccIi.
Here is a list of the colour indications:
Which are the most common colours? In Sweden about 30% of the registered Cockers are blue or red. About 20% are black. A bit more than 50% are parti-coloured.
As a matter of fact, there is one more gene that brings one or more new colours to the Cocker. The colours is not yet seen in Sweden, but is well known in Germany, Denmark and the USA. The ones Iíve seen have been solid coloured sables. It looks very much as if the tan marks have taken over and spread all over the Cocker and just left the ends of the hairs with the original colour. Iím not sure how these colours are inherited. Itís said to be an A-gene that dominates all other genes. If so, there should be solid coloured sables with black ends of the hairs, solids with brown ends of the hairs, roans with black or chocolate ends of the hairs and finally open marks with black or chocolate ends of the hairs. Itís only on the black or brown parts of the parti-coloured Cockers that the sable is seen, not on the white parts.
If you mate a red dog with an black sable bitch you can get 25% of the litter sable coloured. The red dog genes are aaee, he has no genes for sable, A, and not for black, E. The bitch got AaEe. As she is sable coloured she must have at least one dominant gene for that colour, A, but probably not double AA, and she has got genes for black, E. In this case let's guess that she also has a recessive gene for red, e.
Aaee got the gene for sable but as there are no gene for black, E , the sable will not bee seen and the puppies will appear red. The puppies with aaee will be red as they don't have any gene neither for black E nor sable A.