Degenerative Myelopathy

Degenerative Myelopathy (DM) is a progressive neurological disorder that affects the spinal cord of dogs. Dogs that have inherited two defective copies will experience a breakdown of the cells responsible for sending and receiving signals from the brain, resulting in neurological symptoms.


The disease often begins with an unsteady gait, and the dog may wobble when they attempt to walk. As the disease progresses, the dog's hind legs will weaken and eventually the dog will be unable to walk at all. Degenerative Myelopathy moves up the body, so if the disease is allowed to progress, the dog will eventually be unable to hold his bladder and will lose normal function in its front legs. Fortunately, there is no direct pain associated with Degenerative Myelopathy.


The onset of Degenerative Myelopathy generally occurs later in life starting at an average age of about 8 years. However, some dogs may begin experiencing symptoms much earlier, some later, and a small percentage of dogs that have inherited two copies of the mutation will not experience symptoms at all. Thus, this disease is not completely penetrant, meaning that while a dog with the mutation is highly likely to develop Degenerative Myelopathy, the disease does not affect every dog that has the genotype.


Test Is Relevant To the Following Breeds:

DM testing is relevant for all breeds, and is more prevalent in some breeds than others. Dogs of all breeds can be tested for DM, and is particularly recommended in the following breeds: Boxer, Chesapeake Bay Retriever, German Shepherd, Pembroke Welsh Corgi, Cardigan Welsh Corgi, Rhodesian Ridgeback, Poodle, Wire Fox Terrier, Labrador Retriever



Animal Genetics offers DNA testing for Degenerative Myelopathy (DM). The genetic test verifies the presence of the recessive DM mutation and presents results as one of the following:


DM/DM Affected The dog has inherited two copies of the mutant gene and is homozygous for DM. There is a strong likelihood that this dog will develop the disorder. The dog will always pass a copy of the mutation to its offspring.

DM/n Carrier Both the normal and mutant copies of the gene detected. The dog is a carrier for DM and could pass on either allele to any offspring 50% of the time.

n/n Clear Dog tested negative for the DM mutation and will not pass on the defective gene to its offspring.



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