You may see people carrying around their tiny dogs or celebrities clutching them in their purses. Throughout the years, Yorkie’s have been a well known dog breed with long hair and cute faces,
The Dog Journal
DNA/ Genetic Health & Testing
Genetic Testing is the rage! It’s on everyone’s lips right now! Wait! As with all things new and exciting, there might be information out there that’s not 100% accurate. That’s why we decided to dig in and ask the experts our questions. The panel of experts this time includes two dog breeders, a vet, and a genetic vet/expert. We hope you take the time to absorb this information, and when you talk to any of the contributors in the future, make sure to thank them for the great job they did!
The Dog Journal Dec/Jan 2023
Expert Advice Provided by:
Sam Zook, with Crowwoods Homestead, is a longtime Bichon breeder that utilizes genetic health testing and the benefits it adds. Sam has done a lot for the dog breeding industry over the years, and is dedicated to becoming the best dog breeder he can be.
Dr Robert Westra, with Pawprint Genetics has worked in the veterinarian and medical field for years, since graduating from Washington State University in 2008. Dr Westra offers himself as a resource for dog breeders wanting to learn more about animal genetic health.
Michael Glass, from APRI, also a dedicated Newfoundland breeder, gives great insight into how genetic health testing has helped him with his breeding program. Michael has done a tremendous amount of work for the dog breeding industry, and is possibly best known for the amazing conference calls he coordinates.
AKC Claire Wiley, VMD, DACVIM (Small Animal Internal Medicine) Claire Wiley is the Executive Director of the American Kennel Club (AKC) DNA Program, where the AKC harnesses the power of genetics to help breeders breed better dogs. Upon completion of her undergraduate work at Yale University, Dr. Wiley entered the University of Pennsylvania, graduating in 2013 as a VMD. Dr. Wiley was most recently a Clinician Investigator in a combined board-certified small animal internal medicine residency and PhD program at the North Carolina State University College of Veterinary Medicine. During that time, she also served as a scientific consultant for the AKC DNA Program. Aside from her impressive career, Dr. Wiley also has over thirty years of experience breeding, showing, and training Portuguese Water Dogs.
Why should I have my dogs tested for DNA/Genetic Health?
Crowwoods: Breeders get their dogs genetically tested to learn more about their dog’s potential in three main areas: health, traits, and breed. Genetic testing can determine if your dog is a purebred or mixed breed. (Though most registries will not accept this as proof, your puppy customers will!)
Genetic results from trait testing will let you know what colors you can and can’t make with your breeders. Have you ever bred your female to an expensive stud and been disappointed with the colors in the litter? Perhaps the colors you were hoping for were never actually possible between the two dogs. Having both parents genetically tested for color would not only prevent this, but help you select the best mate who will allow your dog to express the most color in their litters. Understanding your dog’s health is so much more than having them pass a vet check at 6 weeks old. Getting them tested for underlying genetic issues allows you to make more informed decisions about their breeding career, and make accurate claims about the health of the puppies you sell.
The primary use of canine genetic testing is to validate parentage. Parentage panels rely upon sets of standardized markers used to establish unique dog identities. The markers vary based on the panel and are not interchangeable. The AKC parentage program has over one million dogs profiled to provide reliable parentage results. This service is important for validating breeder records, and its significance increases as genetic testing broadens. Genetic health test results can be linked with parentage results to ensure accuracy of test results.
Disease and Trait Testing
Disease and trait tests involve collecting DNA and screening for genetic variants related to a specific disease or trait. Many of these tests were developed based on close partnership between parent club organizations and scientists. Some of these tests are easy to interpret with understandable definitions of affected and clear dogs. Others, however, have “incomplete penetrance,” so the presence of a disease-related variant does not always result in disease. For these diseases, an understanding of the prevalence of that affected variant in the population can help breeders decrease the number of dogs with this trait in the future.
Some commercial companies are offering DNAbased ancestry testing based on a library of samples to determine breed or geographical ancestry. These tests are often used by mixed breed owners who are curious about which purebreds are in their dog’s ancestry. Like other human ancestry tests, the library of samples that is used to determine ancestry is based on ownerreported data, which can be flawed. These tests should be used for curiosity regarding the ancestry of a dog of unknown heritage and not as a purity test for purebred dogs.
Lastly, DNA can and should be banked for future testing as technology improves. However, banking is futile without meticulous records for traits that breeders are interested in, such as structure and health. Paired with a semen sample, banking can provide a valuable resource for breed preservation as well. The AKC is building a Purebred Preservation Bank that not only banks DNA, but also preserves semen to maintain genetic diversity for the future. Additionally, the AKC is collecting DNA from detection dogs
while tracking their performance records to establish a robust database linking genetic information and performance. In the future, we may be able to develop genetic profiles that predict working success.
If I test a dog, and he or she isn’t 100% clear of any genetic issue, does that mean I should rehome the dog immediately?
Crowwoods: No, just make sure you are breeding them responsibly from this point forward. Dogs have two genes for every genetic condition. They will be either clear (two clear genes), carrier (one clear and one effected), or be affected (two affected genes). The only dog who will experience symptoms will be an affected dog, unless the condition is dominant. If your dog is clear they can be bred to nearly any mate without a risk to the puppies’ health. Dogs who test to be either carriers or effected should ONLY be bred to a mate who is clear for that condition. This philosophy will ensure that your puppies will never experience symptoms of the genetic issue. You do not need to rehome a dog who is not clear, but you should make sure they are only bred to a mate who is clear for that issue to get healthy puppies. *See chart below
AKC: Elimination of all affected dogs in a breed is not always recommended, as it can result in loss of genetic diversity. Other traits that are beneficial to the breed may be lost as a detrimental trait are bred out. Careful breeding requires education about that trait, especially within the context of a specific breed from a trusted resource.
Should I rely strictly on the genetic health test to determine whether I should keep a puppy for breeding stock?
Crowwoods: No. There are so many things to consider when selecting a new breeder including registration, color, size, health, appearance, personality, and even access to a potential mate. You must be critical and judge your dog as a whole. For example, it is not a good idea to keep a dog who may have excellent health on paper but has dreadful breed standard and a nasty temperament. You may choose a dog who carries one copy of heart failure, over a clear dog if the carrier has a sweet disposition, and perfect colors while the clear dog may have limited colors. Just make note to breed your carrier to a clear male when the time comes!
Pawprint Genetics: First, use your experience as a breeder to evaluate the whole dog. Next, choose dogs that improve the health and quality of the breed you are working with, not just the kind of dog you can get the highest price for. That’s long-term vs short term management. I see poodles being marketed at high prices because they are CDDY clear, yet to look at them they have other negative attributes that I wouldn’t want to bring into my breeding program despite their CDDY status.
As a vet, what can you tell me about the importance of genetic health?
Pawprint Genetics: Since most of the disease we test for have no treatment and can only be prevented through appropriate breeding, the genetic health is very important. At the same time, as we identify disease causing mutation then we are effectively improving any breed by reducing the frequency of these mutations. We also have the ability now to start evaluating genetic diversity but that is a bigger topic for a later discussion.
AKC: Ultimately, it is important to remember that these genetic tests are part of the intricate puzzle pieces that comprise the entire dog. They are tools to help breeders accomplish what they have been excelling at for generations. Just like every tool, the reliability depends on the quality of the test and an understanding of their limitations.
What are some of the most common genetic issues you see in the clinic?
Pawprint Genetics: Common clinical presentation of genetic issues vary by breed. Exercise induced collapse in many sporting breeds like Labradors is out there. Brachycephalic Obstructive Airway Syndrome is another genetic condition affecting bully breeds – which unfortunately – we do not have a test for. Ichthyosis is relatively common skin disease in the golden retrievers and we recently launched a test for a second variant of this condition. And then there is type 1 Intervertebral Disc Disease (IVDD) as a result of the mutation for Chondrodystrophy (CDDY).
How has testing your dogs for genetic health positively affected you as a breeder?
APRI: So, I breed Newfies, and there are only a few things we test for. Most of these three aren’t very common, but I test for them anyway. Quite frankly, even if it is somewhat unnecessary, it still gives me a level of confidence and credibility. For some breeds there are a lot more issues to test for, and those definitely need to do the testing.
One way in which genetic testing has helped me in is for colors and markers. If I’m looking for a specific color or marker, I can now tell which dogs to breed to which in order to get the desired outcome.
Also, if you ever have an accidental breeding, or even a breeding where you use two males to ensure the litter gets the best chance possible, you now can tell which puppy comes from which father. Years ago, breeders would just lie and hope they were right, but now, you can have a DNA test done and you know for sure. After the puppies are born, you’ll need to have both fathers, the mother and the puppies tested, so it can get a little inconvenient, but then again, it beats not knowing.
When you buy in a dog or are looking at buying in a dog, requiring the breeder to do a genetic health and DNA test before you buy can be a great way to ensure you’re getting what you think you’re getting.
How will having my dogs “genetic tested” make my puppies stand out from the ones that are not tested… Do buyers even care?
Crowwoods: Every other puppy out there is dewormed, vaccinated, vet checked, and comes with a 30-day health guarantee. Your puppy needs to be special… being able to guarantee their health for life by showing the parents genetic tests will set your puppy apart! Puppy customers want to know they are buying a healthy puppy who actually is what you say it is. Genetic testing is a great way to prove that. Advertising that you genetically test your dogs is an excellent marketing tool!
Pawprint Genetics: Depends on what you mean by customer. A breeder who is a client of PPG has concerns about what the test means and how to use them to get their program more in line with their priorities. A puppy buyer is concerned with getting a healthy high-quality pet that they can integrate into their household. They care for two reasons. One, nobody wants a dog that will develop a condition that could have been prevented through appropriate breeding. And two, showing a puppy buyer the genetic results increase their confidence in your commitment to producing healthy high-quality dogs.
APRI: Absolutely! Honestly, they probably don’t know anything about genetics, but it’s just great to have something official so that they can not only feel confident about their purchase, but also feel confident that they are supporting an ethical breeder, which they care about. Somebody might ask if the puppies are tested for hip dysplasia, and even though that’s not possible to test for, it gives me the opportunity to explain to them how hip dysplasia works and how to help avoid it.
And not only do they see the tests for the current puppies on my site, but they can see tests for 20 other dogs from the past, and again, that gives them confidence. Even though genetic health is important for your breeding stock, it is also a huge marketing advantage. It’s just another way to offer more for not a lot more work or costs.
How do I test my dogs for genetic disorders, and can I test my puppies when they are 6 weeks of age?
AKC: Many different techniques can be used to sample DNA from a dog, and each option has variations in quality and significance. A blood sample is often used as the gold standard for high quality DNA but require a veterinarian to collect. Diseased white blood cells can also acquire mutations during the life of the dog, known as somatic mutations. DNA collected from cheek swabs are used routinely and are easy for owners to collect. However, this DNA can be contaminated with DNA from bacteria, or even other dogs when nursing or licking other animals. The quality tends to be lower and more variable than DNA from blood. Other samples can be used to collect DNA as well, such as urine, biopsies, or tissues collected during autopsy.
Crowwoods: Companies like Embark Vet, Pawprint Genetics, and Animal Genetics have different pricing, ways to collect the DNA, activate the sample, and return the results. Dogs can be tested at any age. Some companies offer rushed results that can be available in as little as 14 days while other companies take up to 6 weeks to return results. If you want to test your puppies the earlier the better so you have results by the time they are 8 weeks old.
Pawprint Genetics: We have already covered the how to test. The when to t est i s a g ood question. A dog’s genetic material is set at conception. So, you could test from the very first day. Using tissue like umbilical cords makes this a possibility. Swabbing is more complicated for timing and can be contaminated with food and such. Testing usually happens at 4 weeks as this coincides with weaning so it is less of a hardship for the pups to take them from the mom for an hour prior to testing. Even with postal delays our turnaround time is 14 days from the time we receive the sample and we regularly beat that by several days so usually you will get your results from this timetable in time to determine the appropriate destination for the pup.
APRI: I’ve had experiences with most of the companies out there, but I really enjoy working with Pawprint Genetics. Not only are they very knowledgeable and backed by a lot of science, you can always call them and get “small business” service. They’re my favorite.
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Sponsored by Senate Ag Committee chairman Elder Vogel, was introduced and referred to the Senate Ag Committee on May 31. It was presented to the Dog Law Advisory Board at their meeting on June 1, where all comments were favorable, and there appeared to be a broad consensus of support. The bill includes numerous other provisions that enhance the Pennsylvania Bureau of Dog Law’s ability to perform its mission, including more vigorous oversight and inspections of nonprofit and rescue-type kennels. The Pennsylvania Professional Dog Breeders Association (PPDBA), the nation’s oldest professional pet breeders’ association, supports the bill.
My name is, Gail Mirabella, and been asked by The Dog Journal to share
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