Degenerative Myelopathy

Test Overview:

Degenerative myelopathy is most commonly seen in the German Shepherd Dog, although other breeds are also predisposed, including the boxer, Cardigan and Pembroke Welsh Corgi, Siberian husky and the Rhodesian ridgeback. This disease is normally seen around middle age, and in general diagnosis can only be confirmed at post mortem examination. Breed surveys of some predisposed breeds indicate a fairly low occurrence rate, but most experts think this rate is actually much higher, due to the lack of post mortem follow up of the majority of suspected cases. Signs are due to the immune-mediated destruction of a part of the nerves in the spinal cord, leading to loss of these nerve fibres. The first sign is knuckling of the hind feet, and hind limb ataxia. Once the spinal cord damage progresses past this initial stage (termed proprioceptive deficits), the effectiveness (if any) of treatment is much diminished. Hence early diagnosis is vital. Following this initial stage, hind limb reflexes are affected, then weakness in the hind limbs develops, progressing to total paralysis. Once a dog shows these signs it will almost always respond poorly to therapy. Eventually destruction progresses from the middle of the spinal cord to the upper cord and brain stem, leading to forelimb weakness and eventually interference with the muscles of breathing, causing death. Most dogs are euthanased for humane reasons before this happens. Treatment is with specific supplements and drugs aimed at interfering with the immune destruction in the spinal cord, to slow further nerve damage. The effectiveness of this treatment is variable, but is only of benefit if started as early as possible. Once nerves are lost, they will not be replaced. Degenerative myelopathy cannot be cured. A DNA test is available for predisposed pure breeds to carry out screening of breeding animals.


Nervous system / Neurologic - Associated with the brain, spinal cord and nerves


Superoxide dismutase 1 (SOD1) on chromosome 31

Variant Detected:

Base Substitution c.118G>A p.Glu40Lys


Moderate. This disease can cause significant signs of discomfort and/or dysfunction in affected animals. It may involve relatively high treatment/management costs, and can sometimes reduce life expectancy.

Mode of Inheritance:

Autosomal Recessive with Incomplete Penetrance

Recommended Screening:

1. All breeding animals should have a DNA test prior to entering into a breeding program - eg at 1 year of age. 2. Neurologic examination of all animals at annual veterinary check-up from middle age (3-4 years) onwards. 3. Offer DNA testing to all owners of puppies if his parents have not been screened.

Research Citation(s):

Awano T, et al. Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis (2009)Proc Natl Acad Sci;106(8);2794-2799.

Associated Breed(s):

Alaskan Malamute, American Bulldog , American Cocker Spaniel, American Eskimo Dog, American Hairless (Rat) Terrier, American Pit Bull Terrier, Australian Bulldog, Australian Cattle Dog, Australian Cobberdog, Australian Labradoodle , Australian Shepherd, Australian Silky Terrier, Australian Terrier, Barbet, Beagle, Belgian Lakenois Shepherd, Belgian Malinois Shepherd, Belgian Tervueren Shepherd , Bernardoodle, Bernese Mountain Dog, Bichon Frise, Bloodhound, Boerboel, Border Collie, Borzoi, Boston Bulldog, Boxer , Boykin Spaniel, British Bulldog, Bullmastiff, Canaan Dog, Cane Corso Italiano, Cardigan Welsh Corgi, Catahoula, Cavador, Cavalier King Charles Spaniel, Cavoodle, Chesapeake Bay Retriever , Chinese Crested, Chow Chow, Collie Rough, Collie Smooth, Coton De Tulear, Curly Coated Retriever, Dutch Shepherd, English Springer Spaniel, English Toy Terrier, Finnish Lapphund, French Bulldog, German Pinscher, German Shepherd Dog, Golden Retriever, Goldendoodle, Great Dane, Great Pyrenees, Groodle, Harlequin Pinscher, Irish Setter, Irish Wolfhound, Kerry Blue Terrier, King Charles Spaniel, Koolie , Labradoodle , Labradoodle Retrodoodle , Labrador Retriever, Landseer ECT, Maremma Sheepdog, Miniature Pinscher , Miniature Poodle, Mixed Breed, Moodle, Moyen Poodle, Norfolk Terrier , Norwich Terrier, Nova Scotia Duck Tolling Retriever , Old English Sheepdog , Patterdale Terrier, Pembroke Welsh Corgi, Pomeranian, Portuguese Water Dog, Pug, Puli, Rat Terrier, Rhodesian Ridgeback , Rottweiler , Saint Bernard , Scottish Terrier , Shetland Sheepdog, Shih tzu, Shortybull, Soft Coated Wheaten Terrier, Spoodle, Staffordshire Bull Terrier , Standard Poodle, Tenterfield Terrier , Tibetan Spaniel, Toy Poodle, Wallace Bulldog, Welsh Terrier , White Swiss Shepherd, Wire Fox Terrier,