Misjudging Mixed Breeds

March 15, 2011  

Study finds that guessing a dog’s breed is usually wrong, which can have big implications for pit bull mixes

By Micaela Myers

Can you tell a “pit bull” from a Lab-mix? How about from a boxer/shepherd or even a poodle-mix? A recent study that compared DNA analysis with people’s best guesses showed that people who are considered expert in the world of dogs were often way off the mark.

While some of these misidentifications can seem quite amusing at first, it’s a serious matter for dogs who are caught up in the world of breed bans, where mistaking a dog for a pit bull or other regulated breed can be a death sentence for the dog. Hundreds of cities, plus Marine Corps and Army bases, apartment complexes and homeowners’ associations have banned or restricted pit bull type dogs and a number of other breeds. Many shelters won’t even place supposed pit bull mixes up for adoption but instead kill them automatically.

As puppies, Cernun and his littermates were labeled as pit bulls by shelter personnel. DNA test results showed Cernun to be a Bull Mastiff and Boxer mix. © 2010 Jennifer Petit

Victoria Lea Voith, Ph.D., DVM, DACVB, professor of Animal Behavior at the College of Veterinary Medicine at the Western University of Health Science, researches breed identification. One of her recent studies looked at dogs of unknown parentage acquired from adoption agencies. She compared the results of DNA breed analysis to the breeds assigned to the dogs at the time of their adoption. The vast majority of dogs tested were not the breeds people thought they were.

Dr. Voith’s latest study involved showing approximately 1,000 people who are considered experts in the dog world – from veterinarians to breeders to animal control officers – videotapes of DNA-analyzed dogs and asking these experts to visually identify each dog’s breed. Dr. Voith is still analyzing the results, but she says that participants reported being shocked by how difficult it was for them to accurately identify the breeds.

If you’re still skeptical, Dr. Voith points to the book Genetics and the Social Behavior of the Dog by John Paul Scott and John L. Fuller as an example of the complexity of canine genetics. The book shows that mixed-breed puppies often look nothing like their parents or grandparents.

“He had five different breeds of dogs he was crossing and looking at different behavioral measures,” Dr. Voith explains. “When they crossed these purebred dogs, they discovered that many of the offspring (F1 generation) did not look like their parents. There are several pictures in his book demonstrating how different the offspring look compared to their purebred parents. When the F1 generation dogs were crossed, the next generation was even more diverse. It is really amazing.”

Delta’s (left) shelter paperwork lists her as a pit bull, and by default her puppies were labeled as pit bull mixes too. Her son, Harley (right), was DNA tested; results revealed Boxer, Akita and Chow breeds in the mix. © 2010 Jennifer Petit

Given the difficulty of visual breed identification and the fact there are more than 200 breeds, it’s easy for authorities to make mistakes. “Breed specific legislation (BSL) can definitely impact people that have dogs that are not those on a specific breed legislation list because somebody may think that their dog looks like one of those dogs,” Dr. Voith explains.
In fact, there are many documented cases of this happening, with owners forced to sue cities, counties and states, claiming their dogs were wrongly seized under these breed bans.

Dr. Voith’s breed identification research sheds light on the difficult, if not impossible, task of accurately enforcing laws that target dogs based on how they look rather than their actions. These types of studies also highlight major flaws in dog bite statistics, which classify dogs by breed based largely on visual identification.

Rocky was adopted from a humane society that listed him as a pit bull mix. A DNA test revealed 10 breeds—none of them bully breeds.

Visit the National Canine Research Council page on breed identification and download the PDFs of dogs labeled as pit bulls and Labradors to see if you can correctly identify their breeds

However, Dr. Voith points out an even bigger issue with breed bans: even if a DNA test shows that a dog is predominantly pit bull, breed is not an accurate indicator of how the dog will behave. “There’s a wide range of behaviors among dogs of the same breed as well as between puppies in the same litter,” she explains. “So even if you find that a dog has a certain percentage of a breed in it, that doesn’t necessarily mean his behaviors are going to be what is thought to be typical for that breed.”

“The other point is that the behavior of a dog is very much influenced by his environment and how it was raised,” Dr. Voith adds.

These lessons sound a lot like what we try to teach our children: judge people as individuals, not by how they look. Hopefully soon we will begin applying this same logic to our canine friends.

Note: While DNA tests are not 100 percent foolproof, testing companies claim a high level of accuracy, and many veterinarians offer these tests. In addition, it’s important to note that companies do not test for American pit bull terrier, but tests like the Wisdom Panel will show related breeds, such as the American Staffordshire terrier.

« « The Day I Got Profiled | Help Give Courageous Pit Bull a New Out ‘Look’ » »


13 Responses to “Misjudging Mixed Breeds”
  1. Anne says:

    The article is superb, the pictures fantastic! I wish everyone could take Micaela’s closing words to heart: “judge people as individuals, not how they look. Hopefully, soon we will begin applying this same logic to our canine friends.” Thank you for another terrific article!

  2. Barbara Sands says:

    What an excellent article. I am happy to see StubbyDog doing such good work educating the public and bringing stories like this one to our attention.
    We were pleased to see Delta who we adopted last September next to her son Harley. Interesting to learn what his DNA test showed.

    • StubbyDog says:

      Thanks for your comments Barbara. And indeed, the DNA results on Delta and Harley were fascinating. Thank you too for supporting StubbyDog!

  3. HRHTWO says:

    I had both of my dogs DNA tested, as they were considered dangerous under the Breed Restriction Legistation of the area I recently moved to. One of my dogs has 1/4 Dachshound, and 1/4 AmStaff Terrier. No other breed was prominent in her. The other dog is 1/2 American Bulldog, which I knew, and 1/4 Terrier (don’t remember which, but a smaller type), and the rest unidentifiable. I found this very interesting!

  4. HRHTWO says:

    BTW. Regardless, I was required to put up a 100 sq ft cage with concrete floors and roof in my completely fenced in back yard, obtain $100,000 worth of incident insurance listing the dogs on my homeowners insurance, and apply for approval to the county just to be able to have my dogs on my property!!!!

  5. Kristen says:

    A little note of interest: Harley continues to look worried. She and her sister, now named Zubi (nee Harley) and Spirit have a home together, graduated all the way through Advanced Obedience and are doing really well. They are the center of their family life. Zubi still always looks worried.

  6. lwilder says:

    My sweet, kind neighbor just adopted a ‘boxer mix’ puppy. I know boxers well, and trained Schutzhund with shepherds. This ‘boxer mix’ is not a boxer, it’s a purebred brindle pitbull from fighting lines. He’s an aggressive, dominant little puppy, snappy jaws a malinois would envy. This puppy has the temperament only prison guards can train and use, or dog fighting, which is what he was bred for. It is irresponsible to have placed with a family. My neighbor doesn’t have the will or understanding to responsibly own a dog like this, and all we can do is watch this turn into a nightmare.

  7. 3kds_n_a_hdache says:

    Harley is adorable. I love the concern in her face. Is it recommended to raise littermates together?

  8. honeyremedy says:

     @lwilder How do you know he is a purebred brindle pitbull bred from fighting lines? Unless you are a part of the dogs parents breeding you do not know. I know it has been a year, but I think the best option would have been to help her find a good solid trainer instead of sitting back and waiting for a mistake to happen.

    • Cajun says:

      Right on…What is lWilder talking about? I grew up with Boxers. One of them was over 100 pounds, brindle and tough as nails, but a sweetheart too….He was fullblooded Boxer, but he was much more “bullydog” looking than my other Boxer who was of a showdog line. lWilder’s comment is like someone telling me I’m not Irish because I have black hair and olive complexion…yet, I’ve got family in Limerick!