Pet owners commonly assume that purebred dogs are more prone to inherited disorders and that mixed-breed dogs are healthier.
Is this a fact or a myth?
Research suggests that this distinction is not always so categorical.
Are Mixed-Breed Dogs Healthier Than Purebred Dogs?
Pet owners of purebred dogs are given higher pet insurance premiums because their pets may need coverage for inherited disorders. However, the latest data shows that the generalization of purebreds as less healthy and more prone to inherited genetic disorders is not always true.
One study investigated 10 genetic conditions and compared them to see whether mixed-breed or purebred had a higher chance of inheriting them.
The most shocking finding was that most purebred subgroups are just as statistically likely to develop disorders as much as mixed breed dogs are for 7 genetic conditions.
This disproves the common assumption that mixed breed dogs are healthier than purebreds.
Purebreds are more likely to have only 3 out of the 10 examined genetic disorders.
Purebred Dogs' Category
To better understand which dog breeds, have a higher prevalence of inheriting these conditions, they have been categorized into subgroups.
The American Kennel Club has seven groups of dogs depending on the breed’s characteristics and functions the dogs were originally bred for.
The groups and some popular breeds of that category are as follows:
- Hound (Bloodhound, Dachshund, Greyhound)
- Working (Boxer, Great Dane, Rottweiler)
- Sporting (Labrador Retriever, German Shorthaired Pointer, Cocker Spaniel)
- Terrier (Bull Terrier, Scottish Terrier, West Highland White Terrier)
- Toy (Chihuahua, Pug, Shih Tzu)
- Non-Sporting (Bulldog, Dalmatian, Poodle)
- Herding (Border Collie, German Shepherd Dog, Pembroke Welsh Corgi)
Conditions
Certain subgroups of purebred had a higher disposition for developing
Purebred subpopulations do not differ statistically from mixed-breed dogs
Aortic stenosis
Atopy/allergic dermatitis
Aortic stenosis
Skin allergies
Hypothyroidism
Bloat
Bloat
Intervertebral disk disease
Early-onset cataracts
Early-onset cataracts
Dilated cardiomyopathy
Dilated cardiomyopathy
Elbow dysplasia
Elbow dysplasia
Epilepsy
Epilepsy
Portosystemic shunt
Hypothyroidism
Intervertebral disk disease
Hepatic portosystemic shunt
Inherited Conditions that Affect only Certain Subgroups of Purebred Dogs
Aortic stenosis
Aortic stenosis is a narrowing above the aortic heart valve or the aortic valve itself. It is statistically more common in working, sporting, and herding subgroups of dogs.
Bloat
Stomach dilatation or bloat is a serious condition and can be fatal if left untreated. Non-sporting and working subgroups of dogs are significantly more affected by this disease.
Early-onset cataracts
As the name suggests, this condition develops early in a dog’s life by clouding the lens inside the eye, causing blindness. Non-sporting and sporting subgroups of purebred dogs were found to have a greater probability of developing this condition.
Dilated cardiomyopathy
This genetic condition creates enlargement of the chambers of the heart and thinning of the muscle wall. It typically affects large and giant-sized dogs of the hound, sporting, and working subgroup of dogs.
Elbow dysplasia
Large breed dogs are most affected by an abnormal growth of tissues, leading to malformation and degeneration of the joint. Herding, sporting, and working subgroups, especially Golden retrievers, the Newfoundland, German shepherds, Bernese Mountain Dogs, and Rottweilers, are all known to be predisposed to elbow dysplasia.
Epilepsy
Repeated brain seizures are one of the most frequently reported neurological disorders in dogs. In most cases, epilepsy cannot be cured. Herding, hound, and sporting are more prone to developing epilepsy.
Hepatic portosystemic shunt
Terrier and toy grouping have an increased incidence of a portosystemic shunt. This condition is an abnormal connection where blood is diverted around the liver rather than into it. Surgery is often needed to treat and correct the shunt.
Inherited Conditions with Higher Prevalence among most Purebred Dogs
Skin allergies
Atopy or allergic dermatitis is a condition that is dogs suffer from frequently depending on environmental circumstances or genetics.
Hypothyroidism
The underactive production of thyroid hormones can affect a dog’s quality of life in many ways. This disease is not life-threatening and inexpensive to treat.
Intervertebral disk disease
IVDD causes problems with the disks between the vertebrae of the spine leading to neurological issues. This degenerative process can affect the dog’s ability to walk and often requires surgical intervention.
It is interesting to note that although the risk is increased for most subgroups of developing this condition, the terrier subgroup has reduced risk compared to mixed-breed dogs.
Hound
Working
Sporting
Non-Sporting
Terrier
Toy
Herding
Aortic stenosis
Increased
Risk
Increased
Risk
Increased
Risk
Bloat
Increased
Risk
Increased
Risk
Early-onset cataracts
Increased
Risk
Increased
Risk
Dilated cardiomyopathy
Increased
Risk
Increased
Risk
Increased
Risk
Elbow dysplasia
Increased
Risk
Increased
Risk
Increased
Risk
Epilepsy
Increased
Risk
Increased
Risk
Increased
Risk
Hepatic portosystemic shunt
Increased
Risk
Increased
Risk
Skin allergies
Increased
Risk
Increased
Risk
Increased
Risk
Increased
Risk
roidism
Increased
Risk
Increased
Risk
Increased
Risk
Increased
Risk
Intervertebral disk disease
Increased
Risk
Increased
Risk
Increased
Risk
Reduced
Risk
Increased
Risk
Empty cells mean the risk is not statistically distinct from a mixed breed developing the same condition.
Pet owners need to be aware of the health risks and conditions their pet is predisposed to develop. Early screenings and responsible breeding are just some ways pet owners can reduce the prevalence of these conditions among the dog population.
Hence, the common assumption that purebred dogs are unhealthier than mixed breed is not always true.
