Degenerative Myelopathy
The term "degenerative myelopathy" is used to describe a specific degenerative spinal cord disease of mature dogs that results initially in paraparesis but eventually evolves to tetraparesis and cranial nerve signs. This disease is most commonly reported to affect mature German Shepherd Dogs, but it can also affect other breeds of dogs. The cause of this myelopathy is unknown, but may have a genetic predisposition with associated environmental influences.
Age of Onset: Usually, dogs are greater than 5 years of age; however, forms of the disease have been reported in younger animals. In some instances, in animals less than 1 year of age.
Sex Predisposition: Any sex of animal can be affected
Clinical Course:
Clinical signs are usually chronic in duration and progressively worsen over the course of several months to a year. Affected dogs typically present with signs of thoracolumbar disease that gradually progresses to involve the upper thoracic and cervical spinal cord. Clinical signs are typically bilaterally symmetrical.
Clinical signs are usually chronic in duration and progressively worsen over the course of several months to a year. Affected dogs typically present with signs of thoracolumbar disease that gradually progresses to involve the upper thoracic and cervical spinal cord. Clinical signs are typically bilaterally symmetrical.
Clinical Signs:
Posture and Appearance
Dragging or shuffling of the pelvic limbs. There may be abnormal toe-nail wear, specifically of toes 3 and 4 of the pelvic limbs
Movement
Signs are usually evident as abnormal movements of the pelvic limbs. As the disease progresses, the thoracic limbs and (much later) the brain stem will become involved. The degree of paresis is usually much worse, however, in the pelvic limbs.
Proprioception
Paraparesis initially, then progressing to tetraparesis in late stages.
Symmetrical paraparesis is most common.
Spinal Reflexes
Often normal, however, some dogs may develop decreased spinal reflex function, specifically of the pelvic limbs
Special Reflexes (e.g. cutaneous trunci)
Usually normal
Special Functions (e.g. respiration, urination)
Urinary incontinence
Fecal incontinence
Painful Reactions
Should not be painful
Muscle Atrophy
May occur due to disuse of the affected limbs
Pain Sensation
Usually remains intact
Other
Additional clinical signs reported include urinary and fecal incontinence, peripheral nerve signs, respiratory signs, and dysphonia
Posture and Appearance
Dragging or shuffling of the pelvic limbs. There may be abnormal toe-nail wear, specifically of toes 3 and 4 of the pelvic limbs
Movement
Signs are usually evident as abnormal movements of the pelvic limbs. As the disease progresses, the thoracic limbs and (much later) the brain stem will become involved. The degree of paresis is usually much worse, however, in the pelvic limbs.
Proprioception
Paraparesis initially, then progressing to tetraparesis in late stages.
Symmetrical paraparesis is most common.
Spinal Reflexes
Often normal, however, some dogs may develop decreased spinal reflex function, specifically of the pelvic limbs
Special Reflexes (e.g. cutaneous trunci)
Usually normal
Special Functions (e.g. respiration, urination)
Urinary incontinence
Fecal incontinence
Painful Reactions
Should not be painful
Muscle Atrophy
May occur due to disuse of the affected limbs
Pain Sensation
Usually remains intact
Other
Additional clinical signs reported include urinary and fecal incontinence, peripheral nerve signs, respiratory signs, and dysphonia
Spinal cord - Diffuse (Thoracolumbar signs most common)
Association with an autosomal recessive mutation in the SOD1 gene
For breed specific genetic testing follow the link below:
https://vgl.ucdavis.edu/test/degenerative-myelopathy
https://www.gensoldx.com/tests/degenerative-myelopathy-dm/
https://embarkvet.com/products/dog-health/health-conditions/degenerative-myelopathy-dm/
For breed specific genetic testing follow the link below:
https://vgl.ucdavis.edu/test/degenerative-myelopathy
https://www.gensoldx.com/tests/degenerative-myelopathy-dm/
https://embarkvet.com/products/dog-health/health-conditions/degenerative-myelopathy-dm/
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