Degenerative Myelopathy
Benelli’s Story by Lauren Meadows
Agenda
Videos
What is DM?
Occurrences &
Causes
Clinical Signs &
Progression
Diagnosis
Prevention Through
Ethical Breeding
Genetic
Classifications
Highlights
References
Benelli – Declined Mobility
Taken approximately 1 month after we noticed a
significant decline in his mobility.
His hind feet are knuckling over and he is dragging
his toes.
http://youtu.be/H2DlSN9OKoE
1 month later…
Very little improvement even after physiotherapy,
various medications and chiropractic.
Benelli is wearing “boots” for added traction, it was
the only way he could walk indoors.
He has little muscle coordination resulting in unsteady
gait and has loss of hind end awareness when he sits.
http://youtu.be/oYiDQ8sdOI8
What is Degenerative Myelopathy?
-
A progressive disease of the spinal cord
-
Causes demyelination (loss of insulating coating) and axonal
loss (loss of nerve fibers)1
-
The end result is paralysis and loss of sensation in the limbs
within 6 months to 1 year of symptoms
-
Larger breeds are more likely to be afflicted
1[University
of Missouri-Columbia College of Veterinary Medicine]
http://genericlook.com/img/uploads/anatomy/myelination.jpg
DM Occurrence and Cause(s)
Disease is more likely to affect larger dog breeds:
- German Shepherds, Boxers, Rhodesian Ridgeback,
Belgium Shepherd, Old English Sheep Dog,
Weimaraner
- Though it can be found in others (Corgi, Pugs, Terriers)
Average age of onset is between 7 and 14 years
The exact cause is unknown
- May be due to an autoimmune disease similar to
Multiple Sclerosis in humans
- Has been linked to a gene mutation which causes
Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig’s
disease) in humans.
Clinical Signs and Progression
Most commonly begins as a lack of muscle coordination
especially in hind legs:
Crossing over hind legs
Dragging toes
Knuckling over
Diagnosis
 There are no specific tests that will confirm DM
 It is often diagnosed through the process of
elimination:
 If lab work, X-ray, MRI, do not identify another disease
than DM is assumed.
 The only way to confirm the diagnosis is an autospsy,
when the spinal cord can be examined under the
microscope.
 Thus it can be possible to prevent the spread of this
disease through selective breeding and genetic testing
Prevention Through Breeding
 Because DM is a genetic trait, testing and breeding may
significantly decrease the risk of DM
 Testing can be easily performed by a DNA sample sent to
the Orthopedic Foundation for Animals (OFA) in
collaboration with the University of Missouri. There are
others labs that offer similar buccal swab testing made
available to the public.
 The specific gene is the SOD1 mutation
 Dogs can be identified as Normal, Carrier or At Risk
Genetic Classifications
 If a dog carries two normal copies of the gene (NORMAL)
 Highly unlikely to develop DM
 Highly unlikely to pass on the disease to any offspring.
 If a dog has one mutated copy and one normal copy (CARRIER)
 Highly unlikely to develop DM
 Can transmit mutated gene to it’s offspring
 If a dog has two mutated copies of the gene, it is at risk for and
likely of developing DM, and has a 50/50 chance of producing
Carrier and At Risk offspring.
Highlights
 Degenerative Myelopathy is a crippling disease that
has no cure and is lethal
 The occurrence of DM may be reduced through
genetic testing and selective breeding
 As a breeder: test your breeding dogs
 As an owner, ask your breeder whether this testing
had been completed and what were the results
References
In Memory of Benelli
Born a dog, died a gentleman.