A sine qua non disorder is one that is both universal and definitional within a breed. To remove the genes that cause the trait, disorder, dysfunction, or disease would fundamentally alter the essence of the breed.
Any rational and humane breeder would want to remove disease from their breed if given the chance. No Border Collie is benefited by epilepsy or collie eye anomaly, and if we could wave a wand and rid them from the breed, it wouldn’t take much thought to do so.
Alas, there are dog breeds where dysfunction and disease are part of the breed standard or inextricably linked with traits that are required in the dogs. No matter how many DNA tests become available, such diseases will not be removed from the breed because the breeders want them there, require them there, and even cull puppies that are unaffected!
Such disorders are sine qua non to the identity of the breed. If they didn’t exist, the breed would not exist, certainly not as we know them. Unlike CEA or HD or epilepsy, removing a sine qua non disease requires breed standards to be rewritten, not genetic tests. The major obstacle is not genetic, it’s political.
A sample of such diseases and the breeds they are inextricably linked to:
Abnormal cartilage growth causing short legs and trunk:
Bulldog, Corgi, some Jack Russell Terriers, Pekingese, miniature Poodle, Shar Pei, Shih Tzu, Skye Terrier, Swedish Vallhund
Extra digits on the foot:
Beauceron, Briard, Great Pyrenees, Norwegian Lundehund
Pituitary (Ateliotic) Dwarfism
Boston Terrier, Chihuahua, Miniature Dachshund, Italian Greyhound, Maltese, Minature Pinscher, Minature Spaniel, Pekingese, Pomeranian, Pug, Shih Tzu, Toy Poodle, Yorkshire Terrier
Lacking a tail; associated defects of the spine and anus.
(Non-C189G mutation) Boston Terrier, English Bulldog, Miniature Schnauzer;
(C189G mutation) Australian Shepherd, Australian Stumpy Tail Cattle Dog, Braque du Bourbonnais, Brittany Spaniel, Croatian Sheepdog, Mudi, Polish Lowland Sheepdog, Pyrenean Shepherd, Braque Francais, Schipperke, Spanish Water Dog, Pembroke Welsh Corgi
Obviously the severity of these disorders ranges from very minor and unlikely to cause inconvenience in the case of a Beauceron’s extra dewclaws to chronic and potentially lethal conditions like Shar Pei Fever.
Such conditions provoke Qualzucht considerations as there’s precious little other than aesthetic fads to weigh against the potential suffering of the animal. You’ll notice that many of the disorders here mirror those that are enumerated in Qualzucht laws.
For individual analysis of some of these conditions, refer to the “sine qua non disease” category under “health and genetics.”
Beyond the physical, we might also include inbred mental disorders that are definitional of breeds. Ojeriza in the Fila Brasiliero maps to the human mental disorder Xenophobia. Border Collie eye would be considered an Obsessive Compulsive Disorder if a human displayed the same traits.
If you can think of another disorder that is quintessential to a breed’s definition that I have neglected to include, please leave a comment and I’ll be sure to update the list.
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