By Dr. Becker
Back a few years ago when dog breed identification genetic tests -- also called doggy DNA tests and “mutt tests” – were new and novel, many pet owners and veterinarians who tried them were not impressed. This was due in part to actual inaccurate data produced by the tests, but was primarily due to breed test results that seemed to conflict – sometimes wildly -- with a dog’s appearance. For example, if your mixed breed dog happens to look quite a bit like a Basset Hound, it’s disconcerting to receive a test result that doesn’t show any hint of Basset Hound in his DNA.
Visual Breed Identification is an Imprecise ‘Science’
Veterinarians, animal shelters, rescue organizations, and most pet owners have a practical need to settle on breed identification for dogs. This has always been accomplished visually. We pick a breed the dog most closely resembles, and that’s the breed we attach to the dog. That’s why “mutt test” results can be so unsettling – they make us realize just how wrong we can be when we assign breeds by looks alone.
Here’s one great example of visual misidentification, provided by the online Veterinary Information Network, VIN.com:
“Hughes [Dr. Angela Hughes, a veterinarian and geneticist at Mars Veterinary] recalled a case of a dog that looked like a black Labrador retriever that tested as a golden retriever mix, which made sense to her as a geneticist.
“You can lose that longer coat in one generation,” she explained. “Goldens carry a black gene. They don’t express it in their coat because the yellow gene blocks all black. They do express it in their nose, eye rims and the pads of their feet. But the golden is recessive. So if you breed a golden retriever to a dog that doesn’t have the genes for yellow and long hair, you’re likely to have a black dog with a short coat.”
Doggy DNA tests have actually become more accurate over the last five years (though they haven’t been perfected). But the results still astound many people who suspect their dog is a mix of breeds A and B, only to discover she’s actually a mix of W, X, Y and Z. The fact is that nature has built in tremendous variability when it comes to the appearance of dogs – even those of the same breed. When two or more breeds are blended, the lack of predictability in appearance increases dramatically.
Is Knowing My Dog’s Breed Really Important?
Learning the predominant breeds that make up your lovable mutt can be very helpful for both you and your vet in determining what genetic diseases your pet might be at risk for. Different breeds have different inherited disease tendencies, so knowing what disorders to watch out for can help you provide the best care possible for your dog’s health and longevity. And in the event your dog does develop a problem, knowing his genetic background can help guide your vet toward a faster, more accurate diagnosis.
Breed identification information can also be used to consult with a holistic or integrative vet about steps you can take now to help your pet avoid future health issues.
Another reason to learn your dog’s breed(s) is so you can better anticipate and respond to aspects of his behavior you perhaps weren’t prepared for. If you can channel the natural instincts of your dog’s breed into appropriate activities, you can often avoid behavior problems. It can also help you maintain perspective (and patience) if you understand that certain activities your dog performs are natural for the breed and not intended to drive you up the wall.
Another way a DNA test can be helpful, and even a lifesaver, is in the event you encounter breed restrictions or breed-specific legislation where you live (or in a location you plan to move to with your dog). It could be beneficial to know – and be able to demonstrate with DNA test results – the breeds that are and aren’t a part of your dog’s lineage.
Reliability of Breed Identification Testing
According to the VIN News Service, while the science of doggy DNA tests is solid, the accuracy of individual tests depends on the quality of information upon which the analysis is based.
For example, the Canine Heritage test hit the consumer market in early 2007 with the ability to detect only 38 breeds. Any dog tested whose heritage fell outside those 38 breeds would have inconclusive results.
As of mid-2012, Canine Heritage was able to detect 120 breeds, and another test called the Wisdom Panel included 203 breeds. In July 2012, Wisdom Panel acquired Canine Heritage and at the moment, the only test on the market is the Wisdom Panel made by Mars Veterinary. There are four tests to choose from: the Mixed Breed Identification Test, the Pure Bred Certification Test, the Designer Dog Certification Test, and the Professional test which is only available through veterinarians.
According to Dr. Hughes of Mars Veterinary, the Wisdom Panel is accurate over 90 percent of the time in over 200 tests of mixed breed dogs with known ancestry. She acknowledges that “pinpointing more complex mixes than first-generation crosses is difficult.’
If you’re thinking of doing a DNA test on your mixed-breed dog and you have no idea of his parentage – which is the case with the vast majority of pets adopted from shelters -- I recommend keeping your expectations reasonable in terms of learning exactly what breeds and how much of each are included in your pet’s heritage.
To see a sample result from a Mixed Breed Identification Test, go to Wisdom Panel, scroll down to the section titled “What’s Inside My Report?” and click on the sample report.