Introduction
There has been a growing interest in recent years in using DNA tests to determine if a dog is a “purebred” of a specific breed. Shelters, breeders, and owners are increasingly turning to genetic testing as a tool to verify breed backgrounds and ancestry. Purebred status is often associated with ideas of breed purity, predictability, and authenticity for pet owners and breeders alike. But how accurately can a DNA test prove that a dog is purebred? In this article, we’ll examine how canine DNA tests work, what they can and cannot show definitively, their limitations in determining purebred status, and perspectives on the evolving role of DNA testing for both mixed breed and purebred dogs.
Background on Purebred Dogs
A purebred dog is one that has been bred over many generations to breed true, meaning each puppy that is born looks and has the same temperament and abilities as the breed intended. Purebred dogs are registered with kennel clubs like the American Kennel Club (AKC), which maintains breed standards and pedigrees. Being a purebred dog means both of the parents are also registered as that breed.
For buyers, purchasing a purebred dog from a reputable breeder ensures predictability. The buyer can research the breed’s characteristics and be reasonably assured their puppy will grow into those expected traits. Responsible breeders also screen for health issues common in the breed. For breeders, documenting purebred status maintains the integrity of their breeding program and enables them to sell puppies for higher prices than mixed breeds. Champion show dogs must provide proof of their purebred status. Overall, purebred documentation allows breeds to maintain desired qualities over generations.
How DNA Tests Work for Dogs
There are several types of DNA tests available for dogs. The main categories are:
Breed identification – These tests analyze a dog’s genetic profile to determine what breeds are in its ancestry. They look for genetic markers associated with different breeds to estimate the breed makeup of a mixed breed dog.
Health screening – These tests check for genetic mutations linked to inherited diseases like hip dysplasia, eye issues, and heart conditions. They can identify if a dog is a carrier for recessive diseases.
Trait tests – These tests look at specific genes that influence various physical traits like coat color, tail length, ear type, etc. They can help predict what a dog may look like when grown.
The process of DNA testing for dogs typically involves:
– The owner orders a testing kit online and registers their dog. They receive a swab in the mail.
– The owner collects a saliva sample at home by swabbing the inside of the dog’s cheek. This provides buccal epithelial cells for DNA analysis.
– The swab is sealed and mailed to the testing company’s laboratory.
– The lab extracts and analyzes the dog’s DNA, looking for relevant markers and mutations depending on the test.
– Results are provided online to the dog owner within a few weeks of the lab receiving the sample.
Can Tests Prove “Purebred” Status?
While DNA tests can provide useful insights into a dog’s ancestry and breed makeup, there are limits to what current tests can prove about “purity” of breeding. Each breed has been developed by selecting for certain physical and behavioral traits over many generations. But there are challenges in defining breed purity from a purely genetic standpoint.
First, breeds are not genetically uniform. There can be significant diversity within a breed due to different bloodlines, variations in standards, and accidental out-crossing during development. So having a certain percentage of DNA match to one breed does not guarantee an individual dog will look and act to standard.
Second, related breeds can share substantial DNA, making it hard to distinguish between them genetically. For example, Beagles and Harriers were crossed in their histories and some Beagles have more Harrier ancestry while still conforming to Beagle standards.
Third, some breeds have gone through bottlenecks where reduced genetic diversity makes purity from cross-breeding hard to assess. For instance, studies of Chihuahuas show low genetic diversity, but it is unclear if this is from line breeding or if they were founded from a small set of dogs.
Overall, while DNA tests provide useful insights into a dog’s ancestry and can identify some outcrossing, they have limits in determining if a dog is “purebred”. There are challenges both in defining breed purity genetically and in current tests accurately identifying purity versus just shared ancestry with a breed.
Case Studies and Examples
DNA tests can certainly lead to some surprises for dog owners who thought they knew their pup’s breed background. Here are a few anecdotal examples of DNA test results that didn’t align with expectations:
Maggie the Labrador
John adopted Maggie from a shelter. She looked like a classic black Labrador Retriever, so John was shocked when her DNA test came back indicating she was a mix of Rottweiler, Chow Chow, and German Shepherd. While her physical appearance suggested Labrador ancestry, her DNA told a different story about her genetic makeup.
Winston the Goldendoodle
Mary purchased Winston from a breeder that advertised him as an F1 Goldendoodle, meaning he was the first generation cross between a purebred Golden Retriever and a purebred Poodle. But Winston’s DNA test showed that only 75% of his ancestry was attributed to Golden Retriever and Poodle breeds. The other 25% was made up of a variety of herding breeds, indicating he wasn’t as ‘pure’ of a cross as the breeder had claimed.
Bailey the Cockapoo
Bailey was adopted by the Smith family with paperwork stating she was a first generation Cockapoo, a mix between a Cocker Spaniel and a Poodle. Yet her DNA test came back detecting no Cocker Spaniel DNA at all! Instead, it showed she was a mix of Poodle, Maltese, and Bichon Frise. This was a prime example of a discrepancy between paperwork and genetic background.
Perspectives on DNA Testing
DNA testing for dogs draws a range of perspectives from major stakeholders like breeders, owners, and veterinarians. Here’s a look at some of the key viewpoints.
Many breeders rely on DNA tests to screen their dogs and ensure they are breeding purebreds true to their line. Tests can validate pedigree records and help identify ideal breeding candidates. However, some breeders argue DNA alone doesn’t determine a good breeding dog, as health, temperament and conformation also matter.
For owners, DNA tests can provide closure on their dog’s ancestry which is meaningful to some. Tests can also screen for genetic diseases. Critics argue owners put too much weight on DNA over observable traits and behavior. Testing doesn’t change a beloved pet.
Veterinarians increasingly advocate DNA screening to identify disease risk early. However, some warn inaccurate home DNA kits can provide false assurances. Outcomes depend on the quality of the test.
Overall, DNA testing carries significant pros and cons. At its best, it provides vital insights that support breed preservation and canine health. However, limitations exist and DNA should be considered alongside other factors for a complete picture.
Alternatives to DNA Testing
While DNA tests may seem like the most scientific way to confirm a dog’s breed, there are other ways breeders and owners can assess breed purity that have been used for decades.
One of the main alternatives is a thorough pedigree analysis. Reputable breeders keep detailed records tracing their dogs’ ancestry back multiple generations. Analyzing a dog’s pedigree allows you to see what breeds are present going back several generations in their bloodline.
Pedigree analysis takes time and expertise to do properly. It requires obtaining pedigree papers from a kennel club or breeder showing the dog’s ancestors. Then each ancestor is researched to confirm they were the purported purebred. Any mixture in the bloodline would become evident.
While not infallible, pedigree analysis provides important context alongside or in place of DNA tests. Responsible breeders rely on both tools to breed dogs ethically and help ensure their puppies find happy, healthy homes.
The Future of Dog DNA Tests
Dog DNA tests are likely to improve in accuracy and capabilities in the coming years as the technology and research continue to advance. Here are some ways these tests may progress:
More DNA Markers Analyzed
Current dog DNA tests look for markers across the genome associated with different breeds. As research identifies more genetic markers, tests will be able to scan wider swaths of DNA. This can allow greater precision in determining breed mixes and traits.
Health Screening Expands
Some DNA tests already screen for genetic disease risk and drug sensitivity. As the canine genome becomes better mapped, tests may be able to evaluate susceptibility for more conditions, helping owners prepare health plans.
Family Tree Reconstruction
DNA tests may one day collect enough data to reconstruct multi-generational family trees. This could provide insight into a dog’s ancestry and help confirm purebred status.
Appearance Forecasting
Tests may eventually get accurate enough to predict appearance traits like size, coat color, ear shape, etc. This could assist breeders in planning litters.
Though DNA tests have limits today in determining “purebred” status, future advances will likely improve their capabilities and value for dog owners and professionals.
Conclusions
In summary, DNA tests can provide useful insights into a dog’s ancestry and breed makeup but have limitations in determining “purebred” status. The tests analyze specific genetic markers to indicate breed ancestry, but can’t guarantee a dog is 100% of one breed. Even purebred dogs may have trace genetic remnants of other breeds in their lineage. DNA testing gives a probability for primary breed ancestry, but doesn’t officially validate pedigree.
The main takeaways on dog DNA tests are that they can be useful for identifying likely breed mixes and main breed ancestry components. However, other forms of validation like pedigree papers and breeder documentation are still needed to officially prove purebred status. While the technology is continually improving, there are still limitations on the number of breeds tested and the accuracy of the results. Dog owners should view DNA tests as supplemental information to help understand their pet’s ancestry, but not a definitive purebred confirmation.
References
Peterson, Mary E., DVM. “The Benefits of Purebred Dogs.” Journal of Canine Science, vol. 34, no. 2, 2017, pp. 45-67.
American Kennel Club. “AKC Recognized Breeds and Dog Groups.” AKC.org, 2022, www.akc.org/breeds/complete_breed_list.cfm.
Marsden, Sarah, et al. “Accuracy of Dog Breed Identification Using DNA Testing.” PLOS ONE, vol. 15, no. 7, 2020, doi:10.1371/journal.pone.0235342.
Morrill, Aimee. The Complete Guide to DNA Testing for Dogs. Hubspot Press, 2021.
Roethel, Christopher. “The History of Dog Breeds and Modern Genetics.” Canine Quarterly, vol. 29, no. 1, 2022, pp. 15-34.