Purebred or mixed breed?

    Current U.S. presidential debates have temporarily set our country ablaze and left citizens two very opposite and unique candidates to choose from this November election. Meanwhile, in the doggy world, another debate continues amongst dog lovers: purebred or mutt?

    You may have heard people casually comment that “purebreds have more health problems,” or that mutts “are unpredictable.” Data presented in 2015 by The Institute of Canine Biology sought to put an end to the arguments by providing statistics and research on this very subject.

    In summary, here are the results of the research:

    The study by Bellumori et al (2013) used medical records from the veterinary clinic at UC Davis for more than 27,000 dogs and compared the incidence of 24 genetic disorders in mixed versus purebred dogs. The abstract of the paper is included at the bottom of this page.

    Here is what they found: 

    1) The incidence of 10 genetic disorders (42%) was significantly greater in purebred dogs.

    2) The incidence of 1 disorder (ruptured cranial cruciate ligament; 4%) was greater in mixed breed dogs.

    3) For the rest of the disorders examined, they found no difference in incidence between mixed and purebred dogs.


    Aortic stenosis
    Dilated cardiomyopathy
    Elbow dysplasia
    Atopy / allergic dermatitis
    Epilepsy (total)
    Portosystemic shunt


    Ruptured cranial cruciate ligament


    Hypertrophic cardiomyopathy
    Mitral valve dysplasia
    Patent ductus arteriosus
    Ventricular septal defect
    Mast cell tumor
    Hip dysplasia
    Patellar luxation
    Lens luxation
    Epilepsy (confirmed)
    Epilepsy (probable)
    Epilepsy (suspect)

    Although it appears that purebred breeds experience an increase in certain health conditions, further data suggests that are too many varying factors to determine conclusive results.

    This study concluded that purebred dogs have a higher risk of at least 10 of the 24 genetic disorders examined.

    Nevertheless, the findings of this study in the lay press and among purebred fanciers were not so clearly expressed. Some examples:


    • "It has been publicly discussed for years that hereditary disorders would be a direct consequence of the strict selective breeding of pedigree dogs and that for this reason the purebreds would have a much greater risk of developing hereditary disorders than mixed breed dogs. According to the latest research by Bellumori and his group, this assumption does not seem to hold. Indeed many diseases seem to be as common in mixed breed as in pedigree dogs" (Moller, on the MyDogDNA website; pdf)
    • "A new study on the prevalence of inherited disorders among American mixed breed and purebred dogs has negated the common assumption that a mixed breed dog is always healthier than a purebred dog" (Quickfall 2013).
    • "A new study by researchers at the University of California, Davis, indicates that mixed breeds don’t necessarily have an advantage when it comes to inherited canine disorders."  UC Davis press release

    It seems more research is required to provide a definitive answer in regards to whether purebreds are more predisposed to genetic health disorders than mixed breeds. But for those 10 disorders that do seemingly affect purebreds more than mutts, it’s good info for dog owners and/or potential dog owners to have. If you are interested in reading the study in its entirety, visit http://www.instituteofcaninebiology.org/blog/health-of-purebred-vs-mixed-breed-dogs-the-data. What we do know for sure is that whether it’s purebred or mutt, be sure to adopt and save a life! 

    Contact us  661.255.0097  info@nlol.org    PO Box 2240-587 Toluca Lake CA 91610