DNA Lessons Learned: Breed & Health
In recent years, DNA Breed Identification tests have become available to the public and have grown in popularity. As breeders of a newly emerging breed, we were thrilled to be able to use science to prove our legitimacy and to help gain a positive reputation within the online breeder community. These tests quickly became the standard for both breed identification and health.
We treated these DNA tests like a law book. Unfortunately, to the point that some breeders were ostracized when 5-10% of another breed would show up on their dogs’ test results. These tests became so relied upon that many breeders retired dogs out of their program based solely on its results.
As a breed club, we had a unique opportunity to speak with a genetic expert with 30+ years of experience and currently working at one of the major DNA test companies. After this lengthy and frank conversation, we came to a startling understanding…
DNA breed tests are not entirely accurate
The health tests are generally accurate. However, the breed identification tests are not 100% accurate.
Why?
It’s a new science
It’s not a purebred/mutt situation
Many dog breeds have common ancestors
The breed tests only review the genes of previous 4 generations
For crosses like the Pomsky, it sometimes confuses the DNA analyzing algorithms
Breeds diverge and mutate over time
Let’s talk about each one of these issues:
New Science
Canine DNA has really only taken off in the public and breeding world after 2015. There are so many new things to explore and research.
Until the consumers began to purchase the tests commercially, these canine DNA research projects were often underfunded and/or dependent on the focus of the university or science team. Historically canine DNA tests were completed prior to this timeframe, but it was in the private sector, not the wide-scale consumer sector.
As breeders and consumers (“what is the breed of my shelter puppy?”) purchase the tests, they provide these DNA companies the necessary sample pools to increase the accuracy of the DNA algorithms. The larger the pool of information to pull from = the more accurate results.
It also can cause confusion, as a result of DNA tested as 100% pure, it sometimes now shows up with a percentage of a new result, as the tests are adjusted with the new findings.
There are upstanding and cutting edge DNA institutions that refuse to create breed identification tests for dogs due to these inaccuracies, like U.C. Davis and PawPrint Genetics.
Also, just like any other DNA, there can be variants and mutations that will change the results. Just like in humans, science is ever evolving. What is considered ‘fact’ today may be ‘old science’ tomorrow.
Common Ancestors
The further from original Husky x Pomeranian lines that we achieve with our successive generations, additional breeds are popping up in the DNA reports. Why? It’s because we have common ancestors. For example, many recent Breed ID DNA tests are now showing 5% +/- Alaska Klee Kai. The Klee Kai are made up of (Alaskan Husky, Siberian Husky, Schipperke, and American Eskimo). Many Pomsky breeders have added Eskimo into their lines in preparation of AKC submission. This tri-blend shows more of the AKK in the results, as the computer-driven algorithms recognize the common ancestry, and so marks AKK as identified in the DNA report.
Malamute DNA is extremely similar to Siberian Husky, and often were interbred. Thus, genetic markers may appear in the Pomsky DNA report, as Siberian Huskies were clustered with Malamutes for untold generations.
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4806895/
Breed Drift, Selection, Mutations and Diverges
Just like no two dogs look identical, their DNA is not identical. Certain breeder lines are easily recognizable, even though two different breeders’ lines are the same dog breed. The team at the APKC are not geneticists and so although we may be able to understand some of this, it’s better to provide the source information to explain this portion:
Embark wrote an interesting article on Breed Diverges that can be found here. It’s definitely worth the read.
The Institute of Canine Biology wrote this article on Canine Drift and Bottlenecking, found here. They also wrote an interesting article on the prevalence of crossbreed mutations here.
Health Challenges for Breeders
The Institute of Canine Biology wrote an article on the Right and Wrong Way to Use DNA tests here.
In that same lengthy conversation with the popular Canine DNA test provider, it was discovered that the dogs who are swabbed are only tested for the breed relevant diseases. This means that although there are 180+ diseases listed on the website, there are only 5-11 tests that are actually ran on each dog.
What this means for us? The DNA test does not catch everything, and as breeders, we cannot guarantee our dogs to be free of any genetic defects other than the few specific genomes tested. This information was not common knowledge among any of the breeders we gave this information to, regardless of dog breed. With a careful keyword search, we were able to see on the DNA provider’s website that although they market the 180+ diseases, they add in their FAQs that they only test for breed relevant conditions. This is good to note to protect ourselves (Look at your contract on genetic guarantees!) and to help our customers understand our limitations. Mutations happen. Unless each of those mutations are discovered and then tested in the Husky, Pomeranian, and/or Eskimo bloodlines, then it could be present in our dogs without our knowledge.
Also, the current DNA tests that are in the system and what breeders have relied on are changing. The DNA company updates the data as new information is attained.
For example, many breeders have reported that recessive disease genes that were not previously showing in their breeding dogs, are now showing positive as a recessive carrier. What is concerning is that the company does not notify the breeder of the change, and unless a breeder is constantly reviewing their DNA test, they could easily breed a dog that is now a carrier, where previously it has not been. The opposite is also true, where recessive dogs are now showing as clear of any recessive disease genes.
How do we move forward?
As a breed club who heavily relied on DNA tests to be the ruling factor for our foundation dogs, it is a shocking blow to realize that we may have retired perfectly acceptable dogs. Regrettably good breeders have also had their public reputation tarnished by a foundation dog that had previously shown results of one of the genetically similar breeds.
Perimeters are needed around our newfound knowledge. For instance, if there’s German Shepherd or Chihuahua showing in the DNA report, then this is not acceptable on any level. But if there is a Spitz breed showing a small percentage, then this is most likely the result of the above-mentioned breed diverges or similar genetic markers.
NOTE - These are the decisions we will have to make as a collective body of breeders:
Do we choose to remove dogs from our program with the AKK addition, or if it is approved as a long-term exception?
Do we accept dogs that show Malamute, Alaskan Klee Kai, and other Spitz breeds?
If we do accept these, we must decide the perimeters to measure by <5%, <10%, <15%, etc.
Our breed standard vote (Scheduled for end of May 2021) is to provide some structure around what is acceptable, and our breeders need to be part of this process.
The breeder population may have a good grasp on the DNA traits on the DNA reports understood, but that structure and temperament of the dog is lacking. This is what we need to focus on to ensure that we are progressing the breed as we should.
Lessons Learned
Science is ever evolving. What is truth today may not be truth tomorrow.
Commercial DNA companies may not be 100% transparent on their marketing of genetic diseases and what the dogs are actually tested for. Although breeders work towards the healthiest possible breed stock, there may be undiscovered diseases lurking that they have no control over.
Commercial DNA tests are a great tool to have as a guide but they should not be taken as law.
We need to focus on structure and temperament, more than DNA traits for colors.
Check out this great resource: https://cgejournal.biomedcentral.com/articles
