Genetic Diversity Project

Greater Swiss Mountain Dog Genetic Diversity Project

The history of the Greater Swiss Mountain Dog (GSMD) through modern times would lead us to believe that the breed most likely was brought back from extinction in the early 1900s with a relatively small number of individual dogs.  In populations of such limited size, complete avoidance of breeding between individuals with a shared ancestry is impossible.  Therefore some degree of inbreeding is inevitable and further pressures such as desirable trait selection, popular sire overuse, culling of dogs from breeding for perceived or minor issues, among others things will increase the overall rate of inbreeding in the population.  This inbreeding rate correlates to the risk of detrimental effects such as loss of genetic diversity in the population, inbreeding depression and genetic disease.

What is this project?

This project is to help us determine the current level of genetic diversity in the GSMD breed and how to manage that diversity going forward into the future.   The GSMDCA will be partnering with BetterBred LLC to help lead us through the process of having GSMDs tested for genetic diversity, analyzing the test results on an individual dog and overall breed population basis and implementation of breeding advice and tools to help our breeders maintain and possibly improve the genetic diversity of the breed.  During this project, we will also be working with the University of California at Davis Veterinary Genetics Laboratory (UC Davis VGL) who will conduct the DNA genetic testing of the individual dogs (with their DNA test panel of short tandem repeat (STR) markers that will determine genetic diversity across the genome and in the Dog Leukocyte Antigen (DLA) class I and II regions) and provide data analytics.

Why do we need to know the level of genetic diversity in the GSMD?

Unfortunately, we suspect based upon what we know about the history of the breed and review of current day pedigrees that we might have a very limited amount of genetic variability within the breed.  Overall genetic diversity is considered by scientists to be essential to maintain a breed’s health, longevity and reproductive capacity.  Despite our best research and breeding efforts to date, we have some persistent health issues in the breed, such as epilepsy, splenic torsion, uterine dystocia, etc.  Breed health conditions which currently have no DNA test to predict and are not easy or inexpensive to treat. Research has shown that risk of genetic disease increases as genetic variability decreases in a population and homozygosity increases in an individual.  So we believe assessing the level of genetic variability within our breed’s population now, through genetic testing and consultation with BetterBred and UC Davis, will allow us to proactively make recommendations to GSMD breeders to assist them in maintaining genetic variation and a diverse gene pool for the breed.

How will the initial testing be done?

During the first stage of the diversity project (research phase), we hope to obtain samples from 100 GSMDs with as diverse of pedigrees as possible and from disparate geographic regions (world wide) to develop the breed’s baseline data.   It is important to cast as wide as net as possible with the initial sampling of GSMDs, so that the analytics of the overall genetic diversity of our breed’s population and identification of possible outlier individuals are as comprehensive and accurate as possible.  This initial baseline data will not only provide the needed insight into the genetic diversity of our breed, but will assist our breeders in making breeding decisions that will be protect our gene pool going into the future.

To capture as much diversity as possible in the initial sampling, the GSMDCA Health Committee (HC) will be looking to obtain samples from GSMDCA member and non-member breeder dogs in North America, GSMDs which have been imported into North America from other areas of the world and other foreign residing GSMDs that have pedigrees different from those dogs found within North America.  We are asking for breeders/owners who wish to have their GSMDs considered for inclusion in the initial research testing phase of 100 dogs, to complete the genetic diversity entry form linked below and provide a three generation pedigree for review by the HC.  Once the HC has determined the GSMDs which will make up the research phase sample of 100 dogs with a broad range of pedigrees, the owners will be provided with a link to purchase the genetic test through BetterBred.   The UC Davis VGL DNA genetic diversity test sold through the BetterBred website is $50 during the research phase of this project.  As it is vitally important to obtain a wide cross section of GSMDs to test in this initial sampling, the GSMDCA Health Fund will cover $25 of the test to encourage participation.

ENTER GSMD FOR RESEARCH PHASE GENETIC DIVERSITY TESTING

What will the testing results look like?

Once enough samples from GSMDs have been tested during the research phase for UC Davis to establish the Breed’s baseline genetic diversity, they will issue a preliminary results report evaluating the genetic variability of the breed’s overall population.  After which the individual analysis reports will be mailed on each tested dog detailing where it is on a scale from less diverse to more diverse, compared to the overall GSMD population.

Here is an example of the report:

BetterBred will maintain a public database on their website for GSMDs that have completed the genetic testing through this project.  The data base will include the dog’s registered name, Extended DLA Haplotype 1 and Extended DLA Haplotype 2 numbers, Outlier Index (OI), Average Genetic Relatedness (AGR), Internal Relatedness (IR) and Homozygosity by Loci (HL) each compared to the Breed Average.  Here is an example of how the individual dog information is presented in the BetterBred public database (picture supplied to BetterBred by the dog’s owner).

This information database will be available to assist breeders with making breeding decisions and for possible future health research.

How will breeders use the genetic diversity analysis?

Since the early 1900s, breeders have been using pedigree research and statistical calculation of pedigree based coefficients of Inbreeding (PB COI) to determine the level of inbreeding (lack of genetic diversity) present in a planned mating or proposed purchase of breeding stock.  However, this calculation method is not accurate as it is generally based on limited pedigree information (often only 5 to 10 generations of data).  Also it assumes that every puppy in a litter will have the exact same PB COI, even though we know puppies will vary from each other based upon which genes they inherit from their parents.  Now with genetic diversity testing of individual dogs, we have access to the dog’s genome which will give us a much more accurate calculation of COI based upon the dog’s actual genes.

“The breed management software at BetterBred was carefully designed to maximize retention of the biodiversity of a breed as well as to reduce inbreeding in litters.  Due to this, overtime, breeds can enjoy better long term health outcomes and remain viable for the long term.  Individual litters are more likely to be larger, healthier, and have better long term health outcomes as a whole.”  Rebekah Zurbrugg, BetterBred

By knowing the breed’s baseline genetic diversity information, the individual dog’s genetic profile and using the BetterBred breed management software, the breeder will have additional information to:

  • Assess the genetic relationships between two GSMDs being considered for breeding.
  • Identify GSMDs, in the BetterBred database, which are less related genetically to the other GSMDs in the database. This will help identify individual dogs that may be under represented in the breed population.
  • Assess breeding where it is thought that the proposed mates are highly related according to the pedigree but are actually unrelated due to the variation of genetics received from their sire and dam due to recombination. Or on the other hand, mates which appear unrelated via pedigree but are actually closely related due to historical inbreeding.  Put simply, the breeder will be able to more easily determine if proposed line breedings are too tight and if outcrosses are actually outcrosses.
  • Know more about the direction the breedings are taking us by using genetic relationships. For example be able to know which puppies are most like which grandparents, aunts, cousins, etc, and using that information to breed towards or away from specific dogs in the pedigree.
  • Determine if GSMD puppies/dogs being considered for import are actually unrelated genetically to already locally available GSMDs.
  • Help make decisions on which puppies in a litter to retain for breeding. Now breeders will be able to choose the most genetically diverse pups that also meet their other criteria for structure, breed type, temperament and health to move forward into their breeding program.

What is the long term goal of this project?

After the baseline genetic diversity data has been established with the first 100 GSMDs tested, the overall data base will continue to be progressively expanded as more dogs are tested by their owners.  We would eventually like to see all GSMDs that are being bred; be tested and entered into the breed’s database with BetterBred.  Every dog tested makes a valuable contribution to the genetic knowledge of our breed’s current gene pool and the future health of the breed.

For this project to actually make a difference, breeders need to use the information gained to consider genetic diversity when making breeding decisions; mates to select and puppies to keep.  If breeders do not focus on genetic diversity, the breed will lose genes in every generation, and once lost they cannot be replaced within our closed breed population.

Our partnership with BetterBred, will assist with these decisions by providing analysis of our genetic diversity testing and software tools that will assist breeders in obtaining information to make thoughtful breeding decisions.  We are hopeful that this project will help us better balance genetic diversity within the breed, and thereby provide a healthier future for all Greater Swiss Mountain Dogs!

“All dog breeders feel the same.  We want that loyal face looking back at us to be as healthy and happy for as long as possible.  We cultivate generations of our canine companions and would never wish a health issue to become prevalent in our breeds.  We must not only seek “the disease gene”, but also prevent the rise in these deleterious genes by ensuring that no single dog becomes so closely related to the others of its breed that that gene becomes fixed in the population.  We do this by maximizing retention of the exiting biodiversity in each breed.”  Rebekah Zurbrugg, BetterBred

Progress Update (March 2022)

General

The preliminary GSMD genetic diversity report on the first 34 submitted samples has now been released by the Veterinary Genetics Lab at UC Davis.  BetterBred has provided a summary report of the UC Davis findings here

For answers to questions and on-going updates on the GSMD Genetic Diversity Project, please join the Greater Swiss Mountain Dog Genetic Diversity BetterBred Support Facebook group here

Individual

Owners who have previously submitted their Swissies for sampling, should have recently received their individual dog reports via email from UC Davis.  A video to help you understand the results can be found here

To better understand genetics and how the information obtained through the DNA diversity test will assist breeders in making breeding decisions, please watch this free video course provided by BetterBred here

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