Which are healthier; Purebreds or Mutts?

There is a lot to take into consideration when welcoming a dog into the family such as size, maintenance, and health, but with thousands of options ranging from golden retrievers to golden doodles, a mix of poodle and golden retriever, the choice can be overwhelming. Is it true that a dog bred from two separate breeds will be healthier on average?

Researchers set out to find an answer to that exact question. An article published  in the Journal of the American Veterinary Medical Association explained an observational study on 90,004 dogs, looking to find inherited conditions. The team pulled records from William R. Pritchard Veterinary Medical Teaching Hospital over a 15-year period and searched for 24 genetic disorders, in which they found 27,254 of the dogs had been diagnosed. Hip dysplasia, hyperadrenocorticism, among 11 other genetic disorders did not correlate with the dog breed or whether or not it was a mix, but others did. Purebred dogs were found to be more common victims of 10 genetic disorders including elbow dyslplasia and mixed dogs were more likely to only suffer from one disorder-ruptured cranial cruciate ligament.

The study was not absent of flaws though. It most likely suffered from Texas SharpShooter fallacy, as the researchers sought to find over 20 disorders. Due to the large group of disorders being studied, researchers were bound to discover a possible correlation with at least one of them. Chance is also always a possibility and the team did not do a second round of studies following the first conclusion, which may have supported their results further. The team could have received records from more than one animal hospital to slightly lower the results being from chance. A positive approach from the study was the large group size of dogs being observed and fairly recent records from the veterinarian hospital. The study concluded that mixed-breed dogs have a lower chance of inheriting a genetic disorder, but due to some flaws in the study, the results must be approached with caution.

A second study published on PetMD provides a theory as to why a purebred may experience more health complications than mixed breeds. Inherited diseases contribute to large numbers of sick dogs and if two dogs with similar genetic make-up breed the chances of the disease getting passed down increase.

BBC has found that due to the Kennel Club’s rules that a dog must not be bred out of the breed, many dogs were inbred, leading to the genetic disorders that are still present today. Scientists from Imperial College discovered that 10,000 pugs in London only had the genetic diversity of 50 separate individuals as opposed to 10,000. The traits required by the Kennel Club (screw-tail, wrinkled face, etc) have poor consequences in terms of health. Dog breeds were developed by humans selective breeding over the years and as a result some bulldogs can not mate unassisted due to narrow hips or give birth naturally and some with flat faces have difficulty breathing, among other health problems that arose.

In conclusion, it has been found by multiple trustworthy sources, with a mechanism to support the claim, that mixed dogs are less likely to inherit genetic disorders than pure-bred dogs, but there are ways to reduce the chances as well. The dog breeder can assure that neither dog breeding has any pre-existing health conditions and can also look back into the dog’s family’s records. Not all dogs will inherit health complications, but it is a factor to consider when choosing a dog breed.

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