Purebred Dog Breeds into the Twenty-First Century: Achieving Genetic Health for Our Dogs Part 3



Continued from Page 2

A Canine Revolution?

The foregoing prescriptions may sound like a canine revolution. If so, the revolution would consist mainly of integrating many facets of the fancy which now exist in ghetto isolation, or of importing good ideas from other parts of the cynological world. In Europe, for example, many breed clubs have long held responsibilities for their breeds similar to those described above. The only really revolutionary features of this new vision of purebred dogdom are the permanently open studbook and the abandonment of incest breeding, and those represent simple, inevitable acquiescence to genetic reality. If there is one thing we can do which will be of lasting benefit to the dogs we breed, it is to endow each and every one with a healthy, heterozygous genetic outfit. If that is to become possible, the closed studbook must go and inbreeding must go. There are no effective alternatives.

These reforms would require considerable cooperative effort on the part of breeders, breed clubs and the CKC in order to bring them into being. A major part of the job would be to convince Agriculture Canada of the desirability and feasibility of these proposals, followed by amendment of the Animal Pedigree Act to facilitate them. Yet when we consider the threat to the very existence of purebred dogs posed by genetic disease, the economic loss caused by genetic defects, and their widespread unhappy effect, on peoples lives, can we deny that radical and decisive remedial action is required? The goals of a balanced-heterozygous breeding system producing healthy, hardy dogs and a balanced breed identity structure coordinating all the delightful activities of purebred dogdom, would be worth any amount of effort. Let us begin work now to bring those goals into existence! Future generations of breeders and fanciers will be grateful to us for so doing and what is more, we shall be doing the best and kindest thing for our very best friends - our dogs.

 

Postscript

Inevitably some will feel that the suggestions contained in this brief are unrealistic and impracticable, that ideas such as breed autonomy and balanced-heterozygous breeding "will never fly" in Canada. It may be that this brief is slightly ahead of its time; nevertheless, we are about to embark upon a new millennium. Already this country has seen the acceptance and adoption of many concepts that would never have been practicable fifty years ago. The Charter of Rights, settlement of aboriginal land claims, the Internet, the Quebec referendum -- none of these current realities would have been acceptable or seriously foreseeable in the first half of the twentieth century.

Many breeders will reject outright the mere idea of deliberately trying to increase heterozygosity, after so many years in the pursuit of homozygosity through "linebreeding" and frank incest breeding. Others will be horrified by the thought of dismantling the apparatus of the CKC Championship Show. Almost everyone, myself included, will be nervous and dubious about increasing the power and autonomy of breed clubs, based on the past performance of many such clubs. Yet needs must when the devil drives! The genetic situation is dire and the present outlook for many breeds is grave. Something will have to be done. Just now most of the hope and effort rests upon research towards detection of DNA markers for major genetic diseases. Yet those who promote this approach to the problem of genetic defects invariably seem to have a very narrow outlook, treating each defect in isolation. The approach is no different from that of traditional hip x-rays and eye examinations, except that it may be more efficient. The proponents of disease marker detection do not, however, explain how we are going to deal with the problem of diseases which are already widespread throughout a breeds population, or how our gene pools will stand up to successive waves of severe culling as we strive to "eliminate" one widespread genetic disease after another in our small populations bred from tiny founder groups. The population genetics aspect of marker detection, screening and subsequent selection is simply being ignored. As we have already found to our sorrow, those aspects of breeding and genetics which we ignore as being inconvenient at the time emerge later to work us woe.

Now is the time when we must begin a full and open dialogue among ourselves on the topics that have been mentioned in this brief. Now -- before we embark upon a devastating new wave of genetic attrition which could be the "killer wave" that sinks the ship of purebred dogs.

If the more advanced reforms suggested in this brief prove too unpopular for implementation, then so be it. What cannot be done now we may perhaps achieve in time. But at the very least, an irreducible minimum of reform must take place soon if we are to have any hope for the future of our dogs. The most critical item is relaxation of the closed studbook to allow for admission of new foundation stock. We cannot go on selecting rigidly forever and a day from a closed foundation, particularly not if we are to embark upon an era of new selection criteria based on marker research. A breeds gene pool may be likened to a bank account: one cannot go on making withdrawals forever without an occasional deposit (no matter what deficit-spending politicians may think). That some breeders are dead set against outcrossing does not imply that the rest of us should be prevented from introducing new genetic material if we feel it is needed in our own bloodlines. Likewise I think that the restoration of balanced breed identity is also a high priority item, which many people in the fancy are already well-prepared to welcome. Fanciers interest, for example, in useful working dogs instead of mere beauty contestants has never been higher than it now appears to be.

It must also be pointed out that it would be extremely unwise for the CKC to ignore the need for genetic renewal. The Clubs adoption of a hard-line position would carry a high risk of major schism within the ranks of purebred dog breeders. Already independent breed associations and alternative registries exist, promoting genetic excellence and asserting the need to "protect their breed from the kennel clubs"! CKC terms these organizations "dissident registries" although the associations themselves seem to feel it is questionable who is more dissident in view of the hostile position CKC adopts towards their pedigrees and stud books! In any case, the absence of a proactive, cooperative and open-minded response from the Club to the genetic crisis will almost guarantee the creation of alternative associations and stud books, dedicated to the pursuit of genetic excellence on a more practical basis than that offered by CKC. This author, for instance, fears that in order to incorporate new Siberia import stock into his bloodline of working sled dogs he may ultimately be obliged to adopt an "evolving breed" scenario under an independent association. Schism of this kind is perhaps in no ones best interests, but may be unavoidable should the CKC prove intransigent in refusing to reopen stud books to new foundation, as it has done to date. If more "dissident registries" should in fact arise and succeed in producing canine stock to a higher standard of genetic excellence than can be done within CKC, it would greatly damage the Clubs credibility in the public eye.

What is of paramount importance is that we all recognize the true dimensions and gravity of the problems we now face. It is far too easy to ignore genetic diseases, to make excuses, to pay the vet bills and say nothing for fear that others will accuse one of breeding defective stock -- I think practically all of us live in fear of the smear tactics that are so common in the dog world. Yet the truth is that we are all breeding defective stock; the system itself virtually guarantees that. If we believe that to breed defective stock is a bad thing, then we simply must discuss ways and means of altering that system to allow us to restore genetic health. Too many breeders are now reluctantly deciding that "health must be the paramount concern" and abandoning their usual selection criteria in favour of breeding for hips, eyes, blood, etc. A few decades of that sort of breeding will surely do greater harm to breed characteristics than could ever be done by outcrossing. We must now seek to evolve a system which will naturally, almost automatically, produce healthy animals -- so that we may continue on with, or return to, our selection for temperament, working ability, conformation and breed type. Most of all, it is imperative that we start now to discuss and work on the new structures that are needed to facilitate genetic health for our dogs. The next millennium, close as it is, may be too late.

 


Bibliography

Animal Registration Officer, Establishment of a New Breed of Animals in Canada. Agriculture Canada. Ottawa, ON, Canada, 1991.

Bragg, J. Jeffrey, The Seppala Siberian: A Breeders Manual. 1976. Self-published. Vicksburg, MS. USA.

Bragg, J. Jeffrey, "C.K.C. Doesn't Know What to Do About New Siberia Import Dog." Siberian Husky Club of Canada Newsletter. March-April 1995.

Bragg, J. Jeffrey, The Canadian Kennel Clubs 1939 Siberian Husky Breed Foundation. 1996. Self-published. Whitehorse, YT.

Canadian Kennel Club, By-Laws, 1994, Etobicoke, ON.

Carson, Hampton L., "The Genetics of the Founder Effect," in Genetics and Conservation: A Reference for Managing Wild Animal and Plant Populations, Ed. Schonewald-Cox. Christine M., et al., 1983, The Benjamin/Cummings Publishing Company. Inc., Menlo Park. CA, USA.

Chambers, Steven M., "Genetic Principles for Managers," in Genetics and Conservation, Ed. Schonewald-Cox et al.

Chidiac-Storimans, Barbara, DVM, "Beating the System." Dogs in Canada, October 1995. p. 15.

de Boer, Shirley, and Ben de Boer, "How to Breed to Win -- Summary." Dogs in Canada, April 1994, pp. 30-31, 100.

Futuyama, Douglas J., Evolutionary Biology 2d Ed. 1986, Sinauer Associates, Inc., Sunderland, MA, USA.

Goodenough, Ursula, Genetics, 2d Ed. 1978, Holt, Rinehart & Winston, New York, NY, USA.

Hartl, Daniel L., and Andrew G. Clark. Principles of Population Genetics, 2d Ed. 1989. Sinauer Associates, Inc., Sunderland, MA, USA.

Lemonick, Michael D., "Flawed Beauty." Tlme, 12 December 1994. pp. 52-58.

Queens Printer for Canada, 1988, Ottawa, ON. 35-36-37 Elizabeth II, Chapter 13, An Act Respecting Animal Pedigree Associations.

Ralls, Katherine, and Jonathan Ballou, "Extinction: Lessons from Zoos," in Genetics and Conservation, Ed. Schonewald-Cox et al.

"Siberian Huskies Registered." Kennel and Bench, December 1939.

Templeton, Alan R., and Bruce Read, "The Elimination of Inbreeding Depression in a Captive Herd of Spekes Gazelle," in Genetics and Conservation, Ed. Schonewald-Cox et al.

Tudge, Colin. Last Animals at the Zoo 1992, Island Press, Washington. DC., USA.

Wachtel, Hellmuth, "The Evil Might of Hazard." Our Dogs, 21 April 1995. p. 12.

Weir, Mary Jane T., "Proposal Aims at Building Confidence in Purebred quality." Dogs in Canada, April 1994, pp. 25, 27.

 


Glossary

In the hope of helping the reader to understand certain genetic and other terms which may be unfamiliar, I have included this Glossary. It does not explain terms or concepts that have already been explained elsewhere in the brief, as for example, the concepts treated in the section headed "Lessons From Population Genetics." I have included here mostly terms which are technical enough to be omitted from most dictionaries. If the reader finds other unfamiliar words in the brief, their definitions will be found in any good collegiate dictionary.

achondroplasia - a genetic syndrome producing skeletal development resulting in a semi-dwarf phenotype with shortened and distorted limbs; occurring in some breeds (Alaskan Malamutes. e.g.) as a genetic defect, it is selected for as a breed point in others (Basset Hound, e.g.).

allele - an alternative form of a given gene producing a difference in the trait controlled by that gene; some genes have only one allele, some have two, some have multiple alleles for the same trait.

allozyme - enzymes differing in electrophoretic mobility (i.e., which migrate different distances through the substrate when an electrophoresis test is performed) as a result of allelic differences in a single gene; allozyme variation thus indicates genetic variation. One of the oldest lab tests for genetic analysis.

autochthonous - "sprung from the earth," native to a particular region from a very early time. The Siberian sled dog is an autochthonous dog in Siberia. (Pronounced "aw-TOC-thun-us.")

chromosomes - structures within the nuclei of living cells which are made up of nucleotide sequences, the biochemical information carriers which we call genes. All genes exist as tiny portions of chromosomes; although we may speak of particular genes individually, in isolation, they do not exist as separate entities, but are always found as subunits of chromosomes.

cynological - of or pertaining to the knowledge and study of dogs.

deleterious · harmful or injurious.

diploid - the body cells of most complex animal organisms such as birds and mammals all have their chromosomes in pairs derived from sexual reproduction, such that one chromosome of a pair comes from the father, the other from the mother. The sex cells from only one parent have only half the number of chromosomes of cells in other parts of the body: the normal chromosome number is known as the diploid number, the chromosome number of sperm and egg cells is called the haploid number.

disequilibrium - imbalance or instability.

dominant - said of an allele which by itself alone will produce a particular phenotype regardless of which other allele may be present on the other matching chromosome of the diploid pair; thus it takes only one copy of the chromosome to cause a dominant trait to be expressed in the phenotype.

electrophoresis - one of the most useful lab techniques for revealing genetic variation. which came into widespread use in the 1960s. It involves placing sample material (blood, e.g.) on a gel substrate. An electrical field is then applied between the two ends of the substrate, causing protein molecules to migrate through the gel. Proteins with different ionic charge will travel different distances across the substrate. Staining subsequently makes bands of protein in the substrate visible, so that various samples can be "read" in much the same manner as a supermarket bar coded label.

expression - not all genes possessed by an organism will result in detectable physical traits or differences in that organism; the genes that do are expressed. Dominant genes are always expressed, but recessive genes may be present for many generations without physical expression in the phenotype.

fecundity - the number of progeny produced by animals when reproducing.

fertility - the relative degree of reproductive success, i.e. the frequency with which mating is followed by pregnancy.

gametes - the sex cells of sexually reproducing organisms, i.e. spermatozoa and ova.

genome - the total genetic information possessed by an individual, a breed or a species.

genotype - the invisible genetic makeup of an individual organism, which includes alleles which may be recessive and therefore have no visible physical expression.

heterotypic - displaying different types. A breed which has more than one distinct and recognizable set of "type" characteristics is heterotypic.

heterozygote - an organism that possesses different alleles at a given gene locus.

heterozygous - possessing different alleles at a given gene locus.

holistic - relating to or focussing on the entirety of a thing or an organism and the interrelationship of its component parts, instead of emphasizing different aspects or parts in isolation without considering their interactions.

homozygote - an organism that possesses identical alleles at a given gene locus.

homozygous - possessing identical alleles at a given gene locus.

inbreeding coefficient - a number used to quantify the probability that an organism will have identical alleles from the same ancestral source, usually computed by analyzing the pedigree for "loops" in which the same ancestor is found on both the male and female sides of a mating.

lethal - likely to cause or capable of causing the death of an organism. A lethal gene is one which could either cause an aborted fetus or the death of the organism at some later stage of its life.

locus (pl. loci) - the physical location of a given gene on a particular chromosome.

meiosis - the kind of cell division which produces spermatozoa and ova or gametes and which reduces the chromosome number to half the normal complement.

microsatellite - a kind of DNA testing which detects short DNA sequence variations at particular highly variable sites; used in so-called "DNA fingerprinting."

phenotypic - the visible physical expression of an individual organisms invisible genetic makeup.

polymorphism - difference or variation in form, diversity. Molecular geneticists study protein polymorphism, different forms of proteins in an organism indicating different alleles. Polymorphism studies show that from 20 to 50 percent of gene loci in most species have two or more allele forms.

recessive - a gene which contributes to the phenotype only if it is present in homozygous form. It takes two identical copies of a recessive gene to produce the trait it governs in the phenotype. In practice many genes are neither clearly dominant nor recessive, in which case geneticists speak of variable expressivity or incomplete penetrance.

RFLP - "restriction fragment length polymorphism" -- a DNA analysis technique which involves the use of enzymes to break the DNA chain at specific nucleotide sequences: the resulting "restriction fragments" are then analyzed by the use of electrophoresis and blotting techniques. RFLPs are used as markers for known genetic traits and can be employed for genome mapping.

sublethal - having known deleterious effects which by themselves will not usually cause the death of the organism but which handicap it in some way. Several sublethal genes may nevertheless combine to form a "lethal equivalent."

subvital - having known effects which work to reduce the overall vitality and health of the organism.

typology - the study of types or groups of distinguishing characteristics. Typological thinking involves emphasis on visible superficial characteristics, often mere cosmetic traits which have little to do with the health and viability of the animal possessing them.

viability - the relative survivorship of the fertilized ova resulting from a reproductive event. Nonviability may involve ova which simply fail to develop, fetuses which abort, nestlings which die or juveniles which fail to survive to maturity.


Afterword

The author most sincerely hopes that the foregoing brief has in one way or another stimulated or inspired your thinking about the breeding and selection of purebred dogs into the twenty-first century. Our fancy badly needs a responsible long-term perspective, both for our own good as breeders and for the good of our animals.

If you should wish to comment on this brief, or if you should have some urgent unanswered question, the author will be happy to receive your letter at the address given below.

Should you feel indignant or upset after reading this brief, please put it aside for a few days, then read it again. I have introduced some ideas which, although they are becoming commonplace in other parts of the dog world, have largely failed as yet to reach Canada. Those who have accepted the gospel of breed purity inbreeding, and type above all, as published in a multitude of magazine articles and "how to breed" books, may well feel betrayed or insulted! It is not my wish to insult or to upset anyone, but I have nothing against disturbing complacency. We shall all have to rise above our own narrow individual interests and perspectives if we are to save our purebred dog world from genetic disaster.

If this brief -- as I hope it will -- leaves you feeling that The Canadian Kennel Club should be approaching the matter of genetic health in purebreds in a different way or should be considering new ideas, I hope that you will make your feelings clearly known to the Board of Directors by writing to the CKC Director for your region, whose name and address will be found on Page 2 of the "CKC Official Section" which is mailed every month to CKC members along with their copy of "DOGS in Canada."

In closing, I wish the best to all of us as we carry our breeding programs forward into the twenty-first century. 


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