Can You Tell What’s In Your Mix?


While we all enjoy watching the Westminster Dog show to see the many varieties of dog breeds, the American Veterinary Medical Association’s 2012 US Pet Ownership and Demographic Sourcebook reports that half of all dogs are mixes. My friend Tim Francis has a gorgeous, lovable mutt he named Donnie Iris, after his favorite hometown singer. Tim’s a Marine – thank you for your service! – and when he was deployed to Afghanistan the first time, his parents took care of Donnie. As a treat for Tim, they decided to get Donnie DNA tested for some fun information to send with their next letter. Donnie is a big boy – over 100 pounds of energetic muscle – with short hair. I always thought he looked like a Great Dane-Lab mix. When the testing came back, the results were Cocker Spaniel-Poodle mix, making Donnie the world’s largest Cock-a-poo!

Despite the question about DNA testing for Donnie, DNA testing had been shown to be about 99% accurate for pure breed dogs and about 90% accurate when testing dogs that are a mix of two pure breed dogs. As more mixes occur, accuracy is reduced. Most of the time, however, breed identification occurs by dog experts making judgments based on appearance. A recent study showed that breed identification based on appearance is very likely to be inaccurate. In a study published in the American Journal of Sociological Research, 20 dogs were viewed by 923 dog experts, including shelter workers, veterinarians, trainers, and breeders. All dogs were mixes, but participants were asked to determine if dogs were purebred or a mix and, if a mix, what kind of mix. The dogs also received DNA testing to determine what the genetics showed. The results were very surprising:

  • DNA testing showed every dog was a mix. However, 7 of the 20 dogs were identified as pure breed by the experts.
  • The experts usually did not agree with each other about the breed or breed combinations. Experts only agreed on breed for 7 dogs – and their decision differed with DNA testing for 3 of these 7.
  • Fewer than half of the experts’ guesses matched ANY of the breeds identified through DNA testing in 14 of 20 dogs.

Here are some examples of what they found:

  • Experts agreed that one dog was a Labrador retriever. DNA testing, however, found no Lab genes but equal mix of Chow Chow, Golden Retriever, Gordon Setter, and Saint Bernard.
  • A dog identified by the experts as a Corgi was a mix that included American Water Spaniel, Black Russian Terrier, and Pomeranian.
  • A dog identified as a pit bull was actually primarily Chow Chow and French Bull Dog, with a bit of Dalmatian and Great Dane in the mix.

This research is very important for several reasons:

  • The bully breeds are likely to be getting a bad rap. Dog bites attributed to “pit bulls” are likely to be dogs with no bull terrier in the mix. And legislation banning “pit bulls” is likely to be unfair and very hard to enforce since you can’t tell mixes from just appearance alone.
  • When you have a mix of pure breeds and know the parents, you’ll likely have friends and experts alike who question the mix you’re reporting for your dog. Just remember – even experts can’t judge mixes by their cover.

So what’s Donnie Iris? Research says I’m probably wrong in my Great Dane-Lab suggestion. All I know is he’s the perfect mix for a terrific Marine and that’s what really counts.

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1 Comment

  1. I always wondered about the difference. Thanks and great job with your blog!

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