Canton Pomeranians

All my blog readers must understand basic high school biology - the Mendelian theory.  This concept is applied by mostly all animal breeders to their breeding program.  Applying this to BSD, the main controversy will be to determine whether it is a dominant gene or a recessive gene?  I am inclined to think that it is a recessive gene and this is what I call the Realistic Scenario.  But I am sure that a lot of people because of their present nightmare will argue that it is a dominant gene, and this will be what I call the Pessimistic Scenario.

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The Pessimistic Scenario

Under the Pessimistic Scneario, BSD is a dominant gene homogeneously BSD.  The recessive gene would be a dog that is clear from BSD.  The carrier gene must have the appearance of a dominant gene which means necessarily is a BSD dog but would carry the clear gene. This definition of the carrier gene brings about  several inconsistencies. 

1.      From mostly all discussions of BSD, we talk about a BSD carrier.  This means that the dog is a clear dog but carries the BSD gene.  Under the scenario wherein the dominant gene is BSD, the carrier gene would have a different profile:  a BSD dog that carries the clear genes.    I repeat, under the Mendelian theory, … you have a dominant gene; …you have a carrier gene which has the appearance of the dominant gene but carrying the recessive gene;… you have the recessive gene which is the opposite of the dominant gene.  It is not possible to have a carrier of the dominant gene… having the appearance of a recessive gene but a carrier of the dominant gene.  This is simply contrary to the Mendelian theory.

2.     If the recessive gene is to be the clear gene, ie,  clear from BSD, the chart(D) shows that breeding 2 clear partners will necessarily always produce puppies which are all clear from BSD.  This is very again contrary to the general experience precisely because clear poms may produce BSD.  We can only rationalize that they are BSD carriers  -  clear poms that are carrier. 

3.     Based on the chart, since it is the general consensus not to use any BSD dog for breeding, only D becomes feasible.  And yet,  for D, the projected outcome cannot be said to be realistic based on the general experience of breeders.

Accordingly, I am inclined to say that the Pessimistic Scenario is not applicable to BSD in Pomeranians; ie, BSD is not a dominant gene.

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The Realistic Scenario

Under the Realistic Scenario,  the Dominant Gene is a dog homogeneously clear from BSD.  The Carrier Gene is the pom that visually clear, meaning   without BSD but carries the BSD gene.  The Recessive Gene is the BSD dog.  For easier understanding, I have modified the Mendelian Chart - Realistic Scenario below in terms of colors/legend.  This chart shows the probabilities  of  outcome under  various combinations of breeding partners whether they be Clear of BSD, Carrier of BSD or BSD dogs.

From this chart, the conclusion is that as long as you do not use a BSD dog for breeding(A,C,F),  the worst outcome is that your chances of producing BSD is only 25%(F).  This explains why sometimes when we breed two dogs without the bsd problem, they still produce BSD…either because both partners are carriers or  because the BSD of the Pomeranian in question has not yet occurred!  It is precisely for this reason why I strongly prefer using older males because by the time they are 5 years old or more.  They would have passed the more critical period.

In B, if you breed a BSD dog to a 100% clear of BSD(B), none of the puppies will be BSD but only bsd carriers.  In fact, if  the stud dog(or bitch)  is 100% clear of BSD, he/she will not produce BSD dogs at all(A,B,C).

That makes a homogeneously 100% clear from BSD very valuable.  How do we then know that a dog is clear? By simply observing the outcomes of their puppies, if he never never produce BSD even if bred to a BSD,  we can conclude that he is clear. The condition though should be that the sample size complies statistically.  A short cut way, is by test breeding…breeding him back to his daughter….or in case of a female, breeding her back to her son….this will resurrect the recessive gene hiding and lurking in the background.

From the foregoing, it is now feasible to second guess the carriers and the clear dogs.  BSD identification is easy provided thyroid, skin diseases such as fungus, bacterial and parasitical causes, etc  are ruled out.  With the above chart, there will be some sort of predictability rather than panic time!

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This BSD discussion so much reminds me of haemophilia, the royal disease of European monarchs - a hereditary genetic disorder that impairs the body’s ability to control blood clotting and coagulation, which is used stop bleeding when a blood vessel is broken.  A simple lesion would cause a haemopiliac to bleed to death.  This is a rare disease that occurs in 1 in 5,000-10,000 human male births.  It is a recessive sex linked usually occurring in males and very very rarely in females.

English Queen Victoria passed this on to various royal families across the continent including Spain, Germany and Russia.  The male royalties having this sickness, would pass this on to their linebred children since their wives were distant cousins who were carriers.  However, their bastard children from peasant stock would be very healthy, free from this problem…but, eventually being carriers themselves.

No wonder why my breeder friend says that the white (sptizy pets) pomeraninas would easily straightens up her BSD problem.  Somehow, I have been earlier informed that there are some whites has BSD.  Logically, these must be whites whose peasant pet stock has been bred to BSD royalty!

I am inclined to think that BSD is the result of too much IN or LINE breeding continuously generation after generation.  Without or with very little new blood, the breedings becomes weaker…faults emerging…infertility occurring. 

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What then should be our actions be towards BSD elimination?  The answer to this will really depend on your situation re BSD.  How bad is it in your breeding program?

WHEN BSD IS A SERIOUS PROBLEM,   I suggest that you choose a breeding partner based on how clear he or she is from BSD.  Other aspects you want to improve on may have to be postphoned unless you can get a partner that has both wants.  Since you are not using BSD dogs for breeding, worse case would be 25% of your puppies will be BSD.  Accordingly if your dog or the chosen partner is 100% clear from BSD, you will produce zero BSD.

WHEN BSD IS NOT A SERIOUS PROBLEM, OR NOT A PROBLEM AT ALL,  that would mean your dogs are mostly clear or at worse, carriers of BSD.  Ideally, it would be best to breed your dogs within your line or stay within the lines of people you work(no BSD problem).   This will ensure that your stock eventually becomes 100% clear of BSD. However, this may be self limiting because after staying so many generations without new blood, there still a necessity to outcross.  There is also that attraction to breed to other bloodlines who have something that you want and they maybe BSD carriers.  If and when you do outcross, I suggest you breed to an older dog(5 years or more) who still have his coat in abundance and who is not on any kind of BSD medicine.  With a new puppy from an outside breeding which eventually will be maturing to be of breedable age, you may have a new opportunity. Ideally, you should use him on a limited basis when he is young…or test breed him(inbreed him) …………or wait a bit to see if he or his children ever becomes BSD.  OR, after 5 and he still has a fabulous coat, then you should use him a lot. Then you can go back to your line or stay within the line of your new hybrid puppy.

In both situations, I would also consider breeding to a white male or female, preferably from outcross breeding…..  hoping he or she will be 100% free…and that would serve as another insurance against BSD. 

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When a high profile American  ALL Breed judge visited me last year, he suggested that I use a certain BSD dog for stud.  He felt that this dog is so superior compared to the rest in the pom world and that may place my breeding program up to a more advanced level compared to others. He said he had the confidence that I have the capability to go around the BSD problem……plus I had the numbers.  I just kept quiet thinking…and thinking.

After having discussed the Medelian theory above, I am now inclined to risk breeding to that dog one time… considering that since I feel that most of my females are generally clear of BSD, I would be test breeding my females. At the same time, if my conclusions are correct, I will not be getting BSD but rather a carriers of BSD. I would keep the resulting puppy separate from my breeding program until I can better access the situation.  That could bring my breeding program to a discussed higher level….On the down side, I risk BSD on one litter which I can cull….not kill but pet out.

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It has been said that most, if not all the older bloodlines had BSD one way or another.  For this reason, it has been rationalized that all bloodlines today has it, one way or another lurking in their BSD ancestors many many generations back.(Always someone to blame!)   If only there is such a test to find out whether or not a certain dog is a carrier of that BSD gene, it would have been so easy.  However, using the logic of the Mendelian theory,  if you have been breeding for so many generations and you do not use BSD dogs(who eventually do not become BSD), or at worse, carriers, sooner or later, you will have dogs clear from BSD.  The chart says so!

Let us  say at worse, you have a bitch that does not BSD but a carrier and you breed her to another male carrier(F), you have a 50% chance of producing carriers, 25% chance of producing BSD and  25% chance of producing a  clear dog.(First generation).  If they ever produce one BSD dog, you can immediately conclude that both parents are BSD carriers.  You cull the BSD and treat all the rest as carriers suspect(33% probability clear and 67% probability carrier).  Test breed.  Observe the puppies.  Or maybe even breed to a BSD because if your dog is clear, no BSD will result.  If you can intelligently guess which are the clear dogs, you are so much in a higher level away from BSD (A,B,C)…you can eventually have 100% clear BSD free dogs until you outcross again!

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I hope in the process of sharing my thoughts and experiences, I have helped my blog readers access their BSD situation and make their appropriate action plans.   I do not presume to know everything but logically, I think the foregoing shoud be  quite accurate.  I welcome your comments and stand to be be corrected for any  illogical or wrong statements.

December 3, 2010/revised December 21, 2010

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