Spinal Muscular Atrophy
Description or definition:
Canine Spinal Muscular Atrophy (HCSMA) is a motor neuron disease that
cause degeneration of motor neurons in the anterior (near the head)
section of the spinal cord. Motor neurons are the nerve cells that
convey impulses to the muscles to produce movement. Accordingly,
this condition results in significant muscular weakness and
atrophy. A subcategory of the condition called
German Shepherd Focal Spinal Muscular Atrophy often seen in dogs of German
Shepherd heritage is thought to involve a smaller area of motor neuron
of motor neurons causes progressive weakness with difficulty in supporting
weight, reduced reflexes, abnormal gait, muscle tremors, and loss of
muscle tone/mass (muscle atrophy).
initial muscle weakness is observed, the condition generally becomes rapidly
progressive. The condition is considered “accelerated”
if initial weakness is noted prior to 1 month of age and progresses rapidly,
“ intermediate” if initial weakness noted at 4‑6 months of age and
progresses rapidly, and “chronic” if the initial weakness is noted in an
older puppy and progresses slowly. Accelerated
motor neuron disease generally results in paralysis before the age of six
months, and intermediate motor neuron disease by 2-3 years of age.
Dogs with the “chronic” form of motor neuron disease may live well into
their adult lives. Similarly, the effects of focal spinal muscular
atrophy often seen in breeds of German Shepherd heritage can be relatively
mild and slow to progress. Additionally, unlike some other forms of
motor neuron disease, the weakness or paralysis may be limited to the tail,
hind end, or even just one limb.
is based on a thorough neurologic examination, the absence of
abnormalities on routine diagnostic tests, and the progressive nature of
the condition. Specific diagnostic tests might include testing the
dogs reflexes, muscle biopsy, and electronic nerve conduction studies.
is presently no effective treatment for this condition.
to sites about this disease:
This summary provided by:
|Jessica S |
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The information on this website was written by ISSR breeders and other
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information is being provided as a general overview, from information we
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