Degenerative Myelopathy - Statistics To Consider

In the last seventeen years I have had two Boxers with symptoms of myelopathy. One was a confirmed carrier of the mutant gene. The other remains untested. Both were rescued from an animal shelter.
Both lived past 14 years.

That's pretty good for a Boxer and many medium sized breeds. Larger dogs have generally shorter life spans than small dogs.

Since myelopathy  does not manifest itself until a dog has reached his senior years, it is almost impossible to determine whether a larger dog you want to rescue is at risk of myelopathy.
It is also highly impractical when you adopt from a shelter because the dogs are not held until test results of a myelopathy test are available. It can take up to 3 months to get the results.

However, the Orthopedic Foundation for Animals has published a list of breed related test results that can give an interested party some statistic hints of the chances for myelopathy carriers in certain breeds. For Boxers, for example, statistics show this picture:

BOXER
AT RISK	1054	45%
CARRIER	880	38%
CLEAR	396	17%
TOTAL TESTED	2330

It is therefore reasonable to expect that almost half of all Boxers are most likely to develop myelopathy at a higher age. And about 80 percent of all Boxers carry the mutated gene in one combination or other. Only 17 percent are not at risk. This is confirmed by my own two Boxers. Both developed myelopathy at about 13 years of age.

These statistics show indirectly something else: Popular breeds (that sell well) are very likely to be at risk or carry the mutated gene. The popularity of breeds leads many 'backyard' breeders to produce puppies by random choice of partners. They do not test for the gene before selecting breeding partners. The more popular a breed the higher the percentage of backyard bred dogs with all sorts of genetic disorders.

That is the irresponsible part of backyard breeding. I would apply stringent legal restrictions on it that would 'encourage' breeders to act more responsibly. But that is mainly wishful thinking as matters stand right now.
Even feeble attempts to get a handle on backyard breeding have largely failed. One of the consequences are animal shelters that are overflowing with unwanted dogs and cats. I just come from one that houses more than 370 dogs and close to 140 cats. Yesterday the same shelter had over 411 canine inmates.

Oh, how I love backyard breeders.

If you want to check your favorite dog breed for inherent chances of myelopathy visit http://www.offa.org/stats_dna.html?dnatest=DM
PJJ

My service dog Tys testing his new Doggon Wheels

Here is a brief video of Tys taking his first steps in his brand new wheelchair. It will take a while before he really gets the hang of it.

But it beats not being able to walk at all.

We have some newer videos showing him interact with other dogs. Will post soon.
Padre

Dog Breeds Affected By Degenerative Myelopathy

Here is a list of seventeen dog breeds that are prone to get degenerative myelopathy  at a later age. Other dogs may acquire the disease as well. The illness is caused by a mutated gene. Not all dogs with the mutated gene will eventually get myelopathy. Some dogs have two of the mutated genes (one from mother and father each), some have only one. The majority of the dogs with two mutated genes will eventually develop myhelopathy - usually at 8 to 10 years of age and above.
This disease is fatal. There is no known cure at this time despite of claims by websites that hawk phony service dog patches and cures for DM.
The best a dog owner can hope for at this time is to slow down the progression of the illness. Most dogs with DM are euthanized at around 8 to 12 months after first diagnosis. Some can persevere longer and enjoy some sort of a 'new' life in a doggie wheelchair.
There is a test for the disease. It costs $ 65.00 and can be ordered from the Orthopedic foundation For Animals (offa.org).

• American Eskimo Dogs
• Bernese Mountain Dog
• Borzoi
• Boxers
• Cardigan Welsh Corgi
• Chesapeake Bay Retrievers
• German Shepherd Dog
• Golden Retriever
• Great Pyrenees
• Kerry Blue Terriers
• Pembroke Welsh Corgis
• Poodle
• Pug
• Rhodesian Ridgeback
• Shetland Sheepdog
• Soft Coated Wheaten Terriers
• Wire Fox Terrier

The National Academy of Sciences of the United States reported in an article on the research of numerous scientists from a number of famous American universities on the most recent research into the causes of DM and possible treatments. The article was presented by James E. Womack, Texas A&M University under the title

"Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis.

Canine degenerative myelopathy (DM) is a fatal neurodegenerative disease prevalent in several dog breeds. Typically, the initial progressive upper motor neuron spastic and general proprioceptive ataxia in the pelvic limbs occurs at 8 years of age or older. If euthanasia is delayed, the clinical signs will ascend, causing flaccid tetraparesis and other lower motor neuron signs. DNA samples from 38 DM-affected Pembroke Welsh corgi cases and 17 related clinically normal controls were used for genome-wide association mapping, which produced the strongest associations with markers on CFA31 in a region containing the canine SOD1 gene.

SOD1 was considered a regional candidate gene because mutations in human SOD1

can cause amyotrophic lateral sclerosis (ALS), an adult-onset fatal paralytic neurodegenerative disease with both upper and lower motor neuron involvement. The resequencing of SOD1 in

normal and affected dogs revealed a G to A transition, resulting in an E40K missense mutation. Homozygosity for the A allele was associated with DM in 5 dog breeds: Pembroke Welsh corgi, Boxer, Rhodesian ridgeback, German Shepherd dog, and Chesapeake Bayretriever. 

Microscopic examination of spinal cords from affected dogs revealed myelin and axon loss affecting the lateral white matter and neuronal cytoplasmic inclusions that bind anti-super-oxide dismutase 1 antibodies. These inclusions are similar to those seen in spinal cord sections from ALS patients with

SOD1 mutations. Our findings identify canine DM to be the first recognized

spontaneously occurring animal model for ALS . . ."

If you want to know the real facts about the disease and possible remedies and also can handle 'science speak', go to http://www.pnas.org/content/early/2009/02/02/0812297106.full.pdf+html and become an expert in the most up-to-date research into this insidious disease.

 PJJ