Degenerative Myelopathy in Shelties is thankfully, rare. But it is an inheritable, recessive gene that can be passed on to future generations of puppies.
What makes this a difficult disease to control is the fact that symptoms do not usually become evident until the dog is an older adult. This is long after a dog has been used for breeding multiple times.
The
term degenerative myelopathy is descriptive of its effect on the dog. It wears
away (degenerative) the myelin sheath (myelopathy) that surrounds the nerves of
the spinal cord. As that protective covering around the nerves disintegrates, a
variety of symptoms start showing.
The
dog’s neurological function is slowly affected changing his ability to move
normally, until he is unable to walk. He can also develop loss of control of
bowel or bladder. Degenerative Myelopathy in Shelties is the dog’s version of Lou Gerig’s Disease.
There
is no cure and there is no treatment other than palliative (keeping the dog
comfortable). It is progressive and so the prognosis is poor. Many dogs with
the disease may need to be euthanized.
Most
breeds of dogs can carry the genes. As a matter of fact, over 115 breeds in addition to mixed breeds have the
gene for this disease.
How and when Degenerative Myelopathy is expressed varies greatly from breed to breed.
A relatively new DNA test is now available to see if Degenerative Myelopathy in Shelties is present. As a carrier, (where only one of the pair of genes is positive) the parent dog is physically unaffected by the disease but can pass on this gene to puppies. Breed two carrier dogs together and it becomes possible to have puppies that are affected and sold as pets to families unbeknownst to breeder or buyer.
In 10 or so years those families find out they have a dog with the disease
In order to improve the chances that a Yankee Sheltie remains healthy throughout his life, this test has now been incorporated into the medical clearances performed on all breeding stock here. While it may be considered rare, the statistics are so small as to be inconclusive regarding the percentage of Shetland Sheepdogs affected. With careful breeding, however, the percentage of can stay low.
Consider too, even if only one dog in a million is affected, if it happens to be your dog, the statistics don’t matter. So, since it is possible to test and eliminate one disease from all the possibilities, I think it is worth it.