Determining Necessary Tests for Each Breed: Labrador Retrievers

Q: How do I find the DNA tests I should do for my breed? I have Labradors. 

A: Genetic testing has come so far in what feels like a very short time. During my years of breeding, we have gone from doing only eye checks and OFA Hips and Elbows to doing full genetic panels along with the OFA Heart testing. These genetic panels are evolving as more research is being done. 

First, I will caution you to remember that these genetic tests are only one of many tools in our breeding toolbox. For many breeds, DNA tests evaluate only a portion of the diseases and issues we are concerned about. For example, hip and elbow x-rays are phenotypic tests, not genetic, so we can’t know the genes a dog carries based on these x-rays. All we can do is a best guess based on 60 years of using x-rays in breeding programs.

Other breeds have no tests for some of their more concerning diseases. For example, golden retrievers face a serious eye disease called golden retriever pigmentary uveitis that not only has no DNA test, but we don’t even know the mode of inheritance for it. Because the disease shows up later in the dog’s life, early eye exams may not be valid. This is when pedigree analysis becomes important.

In addition, we must also take into account temperament, structure, type, natural working ability, and overall health, like allergies. 

Now, back to DNA tests. Usually, our goal in using DNA tests is to avoid producing affected dogs. This is particularly true for gene tests, through which we can clearly identify both genes the dog carries, and we know the prognosis for dogs with two normal and two mutated genes, as well as carriers that have one of each. Currently, most of our DNA tests fall into this category.

However, the results of some of our DNA tests aren’t as clear, tests for degenerative myelopathy and Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) in boxers. Using these test results is more complex.

Finally, know that the genetics underlying some diseases vary by breed. A disease that might be dominant in one breed may be recessive in another.

There are several places you can look for the DNA tests for your breed. Your starting point should be Good Dog’s listing for your breed’s health levels.

1. Many genetic testing companies like PawPrint Genetics and Animal Genetics, offer breed panels, where they group tests important for each breed. Check the Discounts on the Exclusive For Good Dog Breeders page for discounts. 
2. Some universities, such as UC Davis, offer breed-specific tests, including genetic diversity. 
3. One company, Embark, currently tests each dog’s DNA against all canine tests they have on their chip. Check the Discounts on the Exclusive For Good Dog Breeders page for discounts. 
4. The OFA Canine Health Information Center (CHIC) lists all of the health tests recommended by the breed’s national breed club.
5. If there is a national or international breed club for your breed, its website likely provides information for recommended tests. 

Learning how to use the results of DNA test results is critical to your breeding program and the future of your breed. There are different consequences for breeds and gene pools when we use carriers in our breeding programs. In most but not all cases, this is preferred because carriers either show no signs of the disease or few. So don’t be afraid of the carrier status, simply use your genetic tests as a tool to breed around them.

Additionally, both parents should be tested, not just one. So, do not be afraid to breed to a carrier with a clear. In the case of Labrador EIC (exercise induced collapse) I have even bred a tested clear girl to a non-collapsing but genetically affected dog. This breeding produced all carriers but the breeding produced the breed type I was looking for. So, now I can breed them to clear dogs.

Here are the tests that I use for my Labradors: 

• DNA Color (so you do not produce a DQ color)
• EIC (exercise induced collapse)
• CNM (centronuclear myopathy)
• DM (degenerative myelopathy)
• HNPK (hereditary nasal parakeratosis)
• MCD (macular corneal dystrophy)
• PRA (progressive retinal atrophy)
• Retinal Dysplasia/Oculoskeletal Dysplasia 1 (dwarfism/retinal dysplasia)
• Copper Toxicosis (copper storage disease)