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The science of genetics is a world with new opportunities for the breeder to improve the health of a bloodline. Unfortunately decades of xrays and veterinary evaluations of both phenotype of the dog and Xray's, have been unsuccesful to eradicate Hip Dysplasia. This genetic disease is still prevelant and a challenge for a breeder to stay clear from. Breeding is like a puzzle and the more small pieces you can control, the higher the chance for healthy pups. There are never guarantees, but science is making small steps to help responsible breeders succeed. To make the puzzle even more complex more recent studies have shown the importance of responsible care for the mother and her pups. Epigenetic influences can activate or de-activate genes making the puzzle even more intreguing yet almost impossible to comprehend. 

Genetics 

* The olfactory experience of a parent might influence their offspring even before conception (!). (University of medicine GA, USA 2014)
* Maternal care can influence gene expression (McGill University, Canada 2001)
* It takes 7 generations to change a behavior in a breeding program (TInley Academy, 2023) 
*  Genetic expression can be influenced by the environment , for example the stress level of a pregnant female can influence the gene expression of her offspring. (Tinley Academy, 2023) 

A dog breeder has taken on an immense challenge breeding their perfect dog. Considering the complex web of breed bloodline characteristics, health requirements, work qualities and the influence of the environment on every stage of the breeding process. There are four components in the total picture.

1. Breeding Vision

2. Xray & DNA diagnostics 

3. Compatible stud and dame in health, character, structure and work qualities.

4. Breeding process must be managed with focus on canine welfare in every detail.
    ( mating event, care of pregnant female, birth itself, raising pups and care of lactating female)

DNA health tests are a combination of facts and fiction.

FACT is that these DNA tests from whatever laboratory you choose will be an asset to your breeding program. But don’t fall for the nice shop talk and the fancy website marketing. Research what you really need for your breeding program. I breed Malinois that have been mixed with the Great Dane many generations ago. So it would be prudent to do DNA tests covering the shortcomings from any breed that is within my Malinois bloodline.
You also must not blindly follow everything a laboratory claims. For example, when I started applying the DNA test of VHL genetics on my dogs I was particularly interested in their Hiplaxity gene test. I tried to research their gene and their medical research findings but could not find anything. They claimed in 2017 that the hiplaxity gene had simple heritability. I asked them for their research, they apparently have a patent on this genetic test. But would not open their medical findings to the public. They now have found 3 gene mutations regarding the Hip Laxity. I had countless discussions with a Dutch veterinarian who xrays thousands of dogs a year for hip quality. He said that that genetic test did not have more then maybe 2-5 % influence on the whole hip dysplasia problem. Finally now VHL genetics has adjusted their explanation for the hiplaxity test that it is a polygenetic trait and does NOT have simple heritability. They are finally honest about this specific test. You must be a critical thinker and not plainly believe what laboratories claim.

 

FICTION
Breeders who claim their dog , which has passed a DNA health test, is cleared from the diseases which they are tested for, is not accurate! When breeders claim the above they misinform potential new puppy owners.

For example ; Embark quote about a heart disease gene test DCM 1 and DCM 2: “DCM2/DCM1… is incompletely penetrant, meaning that while having one or two copies of this mutation is thought to confer some increased risk of developing DCM, it is by no means predictive of disease. DCM is a highly complex disease that is modulated by many genetic factors, most unknown.
Which means the embark genetic test for the heart failure disease DCM does NOT predict whether or not the dog will get the disease or not.

Many diseases are multifactorial like Hip Dysplasia. Meaning that it takes different genes, mutations or other influences like hormones or environment, if there is risk for the disease. You must use DNA testing in combination with Xray diagnostics , bloodline history, breed history and knowledge what a DNA test actually truly means.

For example diseases can also have a different level of heritability per breed. Some breeds even have their own gene for a specific disease in a DNA health test. Genes can be breed specific, so if your german shepherd dog carries the eye disease gene PRA connected to the Swedish vallhund, it still does not give you much information. You would then test for all 20+ ocular disease genes to get a real picture. PRA, progressive retina atrophy; each laboratory has a different approach to which ocular disease gene to test for your dog.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



Another example are the 7 single nucleotide polymorphisms SNP’s they found for the Labrador retriever in predicting hip dysplasia, yet this genetic test is not used for other breeds. 

Research in DNA also claims that the genetic picture for hip dysplasia can be different per breed, a very complex problem!! 

 

 

 

 

 

 

 

Lets analyze a couple DNA tests

When you do DNA tests for the Malinois in my opinion you must combine different tests. The Dutch breed club for the Belgian Shepherd variaties recommends the following tests for the malinois (because my bloodline is not an FCI pedigree line, I incorporate more tests then the below to cover different breeds that could exist within my line from ancestry) :
1. Ataxia genes SDCA 1, SDCA 2, CACA, CA1, CJM

2. Cardiomyopathy and Juvenile CM
3. Poly (A) gene SLC6A3 at Laboklin - still discussion on this one
4. Degenerative Myelopathy

5. Inbreeding Coefficiency 

Only then you are thorough and use the DNA health testing to better your breeding program. Do not automatically remove carriers from your breeding program, and do not promise future puppy clients that fully screened and cleared pups are worth more then carriers, or that they are automatically healthier.

DCM, Diluted Cardiomyopathy ….. The Embark laboratory has only DCM1 and DCM2 mutations in their test. But VHL genetics has DCM1, DCM2, DCM 3 available in their testing. DCM3 is specific for the schnauzer, so if you have a mixed breed with a schnauzer in the bloodline I would recommend you add DCM3 to your health testing. There is even a juvenile DCM , seen in portugese waterdogs that I have not yet found in any laboratory screening tests. 

 

 

 

 

 

 

 

 

SDCA, cerebellar ataxia …. VHL genetics has 5 tests to cover this disease, but Embark only tests the early onset cerebellar ataxia version. Laboklin is the one who tests the CACA and recently the new CA 1  mutation, which embark does not yet have in their package. 

VHL genetics is the only one having the hiplaxity and fbn2 tests, small pieces of the puzzle for hipdysplasia. No other laboratories have these. Though there is controversy around this test as it does not give a high prediction level toward the chance of Hip problems.

NCL, Neuro ceroid lipofuscinosis, a central nervous system malfunction; Embark laboratories have the most extensive testing for NCL with 12 tests. Finland only has 5. VHL genetics has 8 versions but you will need to pay extra to test them all. 

Conclusion:

Do your homework. Never claim your tested dog is free of disease because they are cleared in test results, it is more complex then that . True DNA health testing means you might need to test with more laboratories which is more expensive than doing only one laboratory health package. This depends if you have a purebred line or breed a bloodline with a high chance of different ancestry. Read up on latest research, the diseases itself en the influence of each genetic mutation on the health of your dog.

PRA.jpg

Propective Evaluation of a patended DNA test for CHD. (2017)

This 17-marker patended panel the most promising test for CHD so far....

Worldwide Screening for Canine HD; Where are we now? (2012)

40 Years of screening .... OFA/FCI/BVA/PennHip ... low interobserver agreement. Research has revealed 19 chromosomes responsible for HD...

Articles

Veterinairy research report on Hip Laxity  (2020)

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