The "tough mutt" phenomenon is well known among dog owners. The thinking goes that a dog with one or more breeds mixed into its genetic recipe is going to be healthier and more able to fight off a range of health woes than purebred dogs, which sometimes have a more precious reputation.
A new study led by researchers at Texas A&M University examined this common perception to see if … well … that dog could hunt.
The researchers used data from more 27,000 dogs participating in the Dog Aging Project, a citizen science effort that is seeking to track the health metrics of tens of thousands of canines over the course of 10 years. The study focused on the top 25 most common breeds. What they found was that the idea of mixed-breeds being somehow more disease-resistant than purebreds is simply not true.
While there were some differences in health issues between the two types of dogs, the data indicated that overall, both mutts and purebreds suffer from about the same number of health woes. The top 10 conditions most reported for purebreds were: hardened dental plaque; bites from other dogs; extracted teeth; giardia; osteoarthritis; seasonal allergies; ear infection; heart murmur; fractured teeth; and cataracts.
For mutts, the top 10 conditions were nearly the same and occurred at roughly the same frequency, but the cataract and heart murmur categories were replaced with torn/broken toenails and chocolate toxicity. Also, purebreds had more extracted teeth and bites from other dogs, while mixed-breed dogs got more ear infections. Reports of dental plaque and osteoarthritis occurred with pretty much the same frequency for both types of dogs.
Purebreds healthier than mutts
Overall, out of the 53 medical conditions reported, 26 had no noticeable difference in frequency or type between mutts and purebreds. Perhaps most interestingly, owners of purebred dogs actually reported their best friends having no medical conditions at all at a higher rate (22.3%) than mixed breed owners (20.7%), meaning that the purebreds were actually healthier overall than the mutts.
"Dental disease, allergies and osteoarthritis are among the most common conditions for all dogs," said study co-author Kate Creevy. "Owners should work with their primary care veterinarians on a plan to manage dental health. Regular exercise and maintaining lean body weight may help delay, prevent or lessen the impact of osteoarthritis." Creevy is the chief veterinary officer of the Dog Aging Project and a professor in the VMBS Department of Small Animal Clinical Sciences.
Misconceptions
The reason the misconception about the health of purebreds vs mixed-breeds exists, say the researchers, is likely due to the fact that certain breeds of dogs have specific, well-known health issues. German Shepherds, for example, are known to suffer from hip dysplasia, beagles are prone to epilepsy, and poodles get glaucoma at a higher rate than other breeds. When it comes to mutts, it's nearly impossible to classify specific health concerns because of the sheer numbers of cross breeds. This knowledge of breed-specific illness, and its corresponding lack in the mixed-breed world, has no doubt added to the idea that purebreds are more delicate medically than mutts.
Creevy says one of the most important take-aways from the research is that prospective dog owners shouldn't use medical resiliency based on a dog's purebred status or lack thereof as a basis for choosing their next pup.
"People should consider many factors when choosing a dog, including environment, lifestyle, social interactions and physical activity that will be available to the dog," she said. "Planning for both preventive veterinary care and medical care as the dog ages is also prudent. Dog owners should also talk with their primary care veterinarians about the kinds of medical problems to which their new dog might be particularly prone based on breed, size, sex, etc."
Creevy additionally added that she and her colleagues were surprised by the high level of dog bite cases reported in the study. More research is needed, she said, to find out if scientists can isolate particular factors that could up a dog's risk of being bitten.
The study has been published in the journal Frontiers in Veterinary Science.
Source: Texas A&M University
