What’s In a Name? DNA vs. Human Assessment of Pit Bulls

March 16, 2016

Well, it turns out a lot if that name is “pit bull.” In direct contrast to Justice Stewart who said “I know it when I see it.” (Jacobellis v. Ohio, 1964), a recent study in the Veterinary Journal states that those working at animal shelters don’t actually know a pit bull when they see it (which, of course, is understandable since a pit bull is not a recognized breed of dog – but I digress). This can have serious ramifications for potential pet parents (some of whom won’t adopt pit bulls as their next pampered pets), renters and homeowners (who sometimes have trouble getting insurance if they have a pit bull), and anyone who lives in a location with Breed Specific Legislation. But just maybe, the Veterinary Journal got it wrong.

According to the study, shelter workers labeled dogs as pit bulls TWICE as much as DNA breed signatures identified dogs as pit bull-types. The test involved 16 breed assessors at 4 different shelters and 120 dogs. The staff identified dogs as pit bulls 52% of the time while the DNA tests identified the dogs as pit bulls only 21% of the time. This difference clearly raises concern about the subjective nature of those identifying breed types at shelters with the possible negative consequences mentioned above. Many have leapt to the conclusion that the assessors at shelters are simply over identifying dogs as pit bulls; others have pointed out that since pit bulls are not a true breed, the real issue is the need for a standard tool by which to make the assessment. In any event, both these efforts are an attempt to get the human assessment numbers to match the DNA numbers.

But until we can get the human assessment to match the DNA assessment, what should we do? Should every shelter dog that someone might think is a pit bull have its DNA tested? That’s bound to cost a lot of money at generally cash-starved shelters.  Moreover, one wonders if the this would even be money well spent because built into this entire conversation is the assumption that the DNA testing for breed identification is accurate (otherwise what’s the value of comparing it the visual assessment?). Well, it turns out that this assumption might need to be re-thought. According to the study, “The commercial DNA testing laboratory used in the study reported an average accuracy of 84% in first-generation crossbred dogs of known parentage. The accuracy of the test in dogs with more than two breeds and in dogs lacking any purebred heritage is unknown.” (emphasis added).

So as I read this it means that for the majority of dogs that end up in a shelter, those probably lacking purebred heritage and made up of more than just two breeds, the accuracy of the DNA test is simply unknown! What makes us think that the DNA test is any more accurate than the assessors? Maybe the DNA test is actually less accurate? Given this, as much as we like to put our faith in science and as much as I like the litany of CSI shows on T.V., maybe, just maybe, we need to have more faith in our fellow human beings.

Thanks for reading.

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