Saturday, September 26, 2015

How Accurate are Breed DNA Tests?

Yesterday's post about "box checking and pigeon-holing" in the world of Pit Bulls has someone, rather predictably, pointing to a "study" of multi-mixed dogs that has been paired against "breed DNA tests" and compared to some unknown group of "dog experts."


My first click turned up a dog that the DNA tests
said was made of 5 breeds, including "Glen of Imaal" terrier, one of the rarest breeds of dogs in the world. I laughed. Next!

And next was even more absurd: a dog described as 25% Beauceron, 25% Boxer, 15.03% Ibizian Hound, and 12.96% Chinese Crested. Notice the precision! Notice the rarity. 

If you cannot smell a massive pile of steaming bullshit when standing neck deep in it, I cannot help you. This is what Maddie's Fund does? Good lord, please tell me they do better work than this!

I am not sure what a dog expert is in this context, but since there are 500 of them, you can be sure they are not Pit Bull experts. In fact, it seems they are a mix of poorly educated and low-paid shelter workers, dog groomers, dog breeders, and vet techs, along with a few vets and perhaps one or two dog trainers. Any of them actually know much about Pit Bulls? Probably not. These are the kind of folks who, if shown a Patterdale Terrier, a Jagd Terrier, or an Italian Greyhound would start typing "Chihuahua". They are "experts" by dint of owning more than one all-breed book.

Jay Jack, over at Three Bad Bullies and Next Level Dogs actually does know about Pit Bulls, and he writes about the "Pit Bull identity crisis," in the no-bullshit manner that someone who smells of dog and sweat, rather than lamp and ink, actually has. Read the whole thing.

This previously mentioned "study" embraces the ridiculous practice of showing folks a single picture of a dog, devoid of scale.

That's the kind of paper-hanging stuff we see all the time in the world of dogs. I myself sat through an entire lecture of someone showing snapshots of dogs as she told the group what every dog was feeling at the moment the picture was taken. No, she could not remember what was actually going on when the picture was taken. She was "reading their expressions" now. It seems she had culled through thousands of pictures and was now making up the story to fit the picture based on the set of the tail, the lay of the ear, the look in the eye, etc. This was all being done from static pictures, and it was very amusing to me, as I was reminded of those Beyoncé action shots taken at her Super Bowl performance. Let's get Stanley Coren to interpret those!

The part that was most amusing about this "study," however, is that it uses breed identification DNA tests to "tell us" what breed a dog REALLY is.

It is to laugh.

Breed identification DNA tests are a sure-fire way to make money for those who sell them, including veterinarians who are paid for product endorsement.

But do they work?


In fact, the results shown below are common: a pure-breed dog comes back as being a vague pastiche of three or four breeds.


Breed DNA tests
are not too different from Gypsy Fortune telling, Fortune Cookies, the I-Ching, Numerology and Tarot Card reading: If you give a vague-enough answer, the believers will rationalize whatever result you give them, pounding the square peg into the round hole.

This is especially true for mixed-breed dogs. The folks sending in their dog's DNA for testing here do not care what the answer is, so long as it answers the question. Even an obviously wrong answer gives them a story to tell when someone, inevitably, asks: "What kind of dog is that?"

So what's going on? It's pretty simple: there are hundreds of breeds of dogs, but the DNA tests only definitely ID's a few dozen. The gaps are "filled in" by claiming a dog is a cross of this and that.

But what about the Mars Veterinary WISDOM Panel™ MX or their even newer scam, the WISDOM Panel™  "Professional" that the vets are selling? Surely those veterinarian-administered test works well, right?

Ughh .... NO.

But don't take my word for it.

Mars Veterinary's own web site says the tests are pure crap. Or, to be more precise, they say that if you actually KNOW what AKC breed of dog you have (because you have pedigree papers for your dog going back to the start of the registry more than 120 years ago) then they cannot help you.

But if you don't know what breed of dog you have, then they can positively tell you what you have.


Whiskey. Tango. Foxtrot.

You're kidding, right?

Nope. Read it yourself here (2009 text lifted from earlier post):

Why can't this test detect purebreds?

The WISDOM Panel™ MX test was designed to determine the breed makeup of mixed-breed dogs. Its development involved the analyses of more than 19 million DNA markers from more than 13,000 purebred and mixed-breed dogs to best tell breeds in a mixed-breed dog apart.

In order to determine if a dog is a purebred, Mars Veterinary would ideally need DNA samples that cover all family lines for each breed of purebred dog. But since their focus was the development of a test capable of accurately determining the breeds in a mixed-breed dog, they did not focus on collecting such a catalogue of purebred dog DNA samples.

What's that mean? Not a damn thing! It's poppycock. It's typing by a monkey. It's stupid on stilts, with a side-order of bunko and larceny.

It's the get-out-of-jail card the company can point to when their DNA "test" is shown to be inaccurate, pure crap, and a complete fraud.

In fact, the question itself is paired with this question on the MX web site: "Is Mars Veterinary worried about lawsuits?" This is their answer: Our test is so worthless we cannot identify your breed of dog if it is pure-bred. Our test only "works" when you have no idea what breed of dog you have.

So, NO: dog breed DNA tests do not work.

Save your money. Or better yet, donate what you would have spent on this near-worthless test (about $150) to the local no-kill animal shelter.

1 comment:

seeker said...

Since most of the terrier breeds were originally owned by farmers who bred for function, I daresay that a Jack Russell or Rat Terrier would come back as Old White Terrier, Bull Terrier, Border Terrier, Whippet, maybe some dachshund et al. Note all the terrier types. I know of people who put Jacks to PitBulls for hog dogs, and some put them to Beagles for voices. Farmers make what they need. So as far as I'm concerned, the DNA is a bunch of hooey. Just like the one for people. We're all just honest mutts at the end of the day.

Debi and the Jack Rat Pack.