“Mutt Testing” the Motley and the New Veterinary Politics of Breed Identification
In 2007, canine geneticists threw veterinarians and dog owners an unexpected bone. After spending years mapping the entire canine genome, they’d arrived at a novel application for their findings. They’d make use of their accumulated knowledge of the specific genes that served as markers in particular breeds of dogs to help suss out the true purebred provenance of even the motliest of mutts.
These so-called “mutt tests,” officially termed dog breed identification genetic tests, were the very first of their breed. Which is probably why the results seemed a bit sketchy. I mean, it was hard to look at a long-legged, short-nosed dog and consider Chihuahua and Beagle an acceptable solution to the problem of questionable parentage.
It was this kind of off-the-wall answer that left dog owners feeling fleeced and veterinarians scratching their heads.
A New Way to Look at "Mutt Tests"
Fast-forward five years and the landscape’s changed. The tests have been continually refined for greater accuracy. Apparently, more purebred testing leads to more genetic markers, which translates into more credible results.
Now, that doesn’t mean the tests are perfect, and it certainly doesn’t mean the results won’t shock, dismay or confound you. Indeed, the theoretically vast variability in looks in just one litter out of two different purebreds would truly amaze you. Despite the still-prevalent doubt, these tests are getting a whole lot closer to the truth… more so every day.
Which is why veterinarians like me are starting to look at them in a whole new light.
While I never doubted the fundamental science behind the tests, I confess to having once been a devout skeptic of their relevance. I mean, who cares if it’s a Cocker Spaniel, Poodle, or Portuguese Water Dog? What difference does it make except to potentially perpetuate the notion that mixes are in need of definition and, by inference, that purebreds are preferable?
5 Reasons Why Genetic Testing Is Good
But now I believe I’ve been mistaken to disdain the utility of greater genetic certainty. After all, it’s good for at least three things:
1. Assessing the risk of specific genetic diseases known to afflict the purebreds in a mixed breed’s ancestry can be very helpful to veterinarians hoping to direct pet owners toward appropriate screening tests and diagnose illnesses more efficiently.
2. Knowing which breed or class of breeds a mixed dog hails from can help head off big behavior issues by channeling his drive in a more natural and effective direction. Doing so might just save him from shelter relinquishment or even untimely euthanasia.
3. Breed specific legislation (BSL) remains a hot topic in many municipalities around the world. Despite the science supported by the American Veterinary Medical Association (AVMA) and the US Centers for Disease Control and Prevention (CDC) showing no evidence of any breed’s inherent propensity for violence, thousands of dogs are put to death every year for the sin of semi-resembling a specific breed the community deems problematic.
4. Given all three above circumstances, understanding our mixed breed dogs’ true parentage might well save some lives — and perhaps even help erase negative stereotypes about so-called “bad” breeds.
5. It’s this last issue that recently turned heads in my profession after a paper was published in the Journal of the American Veterinary Medical Association (JAVMA) titled, “Rethinking Dog Breed Identification in Veterinary Practice.”
Visual Identification Is Not Enough
Their goal was simple but decidedly counter to common practices in veterinary hospitals throughout the U.S. While most veterinary practices choose to assign a breed or breed cross to nearly every patient (in medical records, for municipal licenses, health certificates for travel, etc.), the authors convincingly argued we omit the visual breed ID in the case of mixed breed dogs whose parentage is unknown and for those whose purebred status is questionable.
Referencing canine genetic studies demonstrating that dogs’ physical appearance (phenotype) within the same litter varied enormously from their parents,’ the authors’ agreed with genetic researchers who concluded that mixed breed dogs’ genetic underpinnings could not be determined effectively based on their appearance.
This conclusion is in stark contrast to a conventional wisdom advancing the notion that dogs’ purebred heritage can be readily discerned from their physical appearance.
Which would be an innocuous concept if dogs’ very lives weren’t depending on an erroneous assumption even veterinarians have been perpetuating since the dawn of pet keeping.
After all, dogs can die if they’re assumed to be a Pit Bull mix instead of a Bullmastiff, American Bulldog, or Bull Terrier cross. In fact, I know one dog living in Miami whose parents were definitively known to be a Boston Terrier male and a Boxer female. Yet she was forced out of the county (lest her owners face fines and her eventual euthanasia) after county officials deemed her a Pit Bull mix.
But it’s not just breed bans we have to contend with. Homeowner’s insurance policies are problematic here too. As of three decades ago, these carriers began adopting policy exclusions for certain purebreds, including everything from German Shepherds and to Boxers and English Bulldogs too; and, to add insult to injury, all of their crosses.
Which is terrible and unjust, of course, given all the evidence now at our disposal. Hence, why the new politics of breed ID would see veterinarians abandon old ways in favor of a noncommittal approach to breed identification, or at least using DNA testing in place of visual assessments to provide a more accurate estimation of the breed.
In other words, let there be no record of any veterinarian or vet staff’s visual breed “guess.” Because not only is it probably wrong, as the science of genetic testing and other research is informing us, if it’s on record that a dog is a mix of x, y or z, the possibility of an untoward legal or financial outcome remains.
It all makes sense. But will veterinarians alter their behavior? Given the average human’s resistance to change, probably not fast enough. Which is why posts like these will hopefully serve to educate owners on the need to ask that their veterinarians leave out any reference to breed in medical records if no definitive evidence exists.
Here’s hoping we’ll all change our ways. Because ultimately, too many dogs’ lives may depend on it.