Front Matter

Chapter 17 Diagnosis of and Treatment Options for Disorders of the Spine 449

Surgical and nonsurgical options
for spinal cord conditions

Surgical considerations

Almost all surgical interventions of the spine
involve decompression of the spinal cord and/
or stabilization of the spine for realignment and
preventing further impingement of the neural
tissues.
In those cases where spinal cord integrity is
presumed intact, determined by the animal’s
response to noxious stimuli, the results are
often favorable. This is true even though a wide
choice of surgical procedures has been recom­
mended. There is a tremendous amount of
plasticity in the neural tissues and, even in the
face of significant permanent spinal cord
damage, an acceptable recovery can occur.
Successful outcome is related to the rapidity of
the spinal cord compromise and the amount and
chronicity of the spinal cord compression. This
was first clearly demonstrated by the balloon
compression experiments performed by Tarlov
in the 1950s (Tarlov, 1954). These variables do
not determine successful outcomes based on
absolutes and many dogs have recovered full
function unexpectedly when given time.

An issue that has not been given adequate

attention is determining prognosis in the recov­

ery process of the canine athlete or working

dog. These dogs depend upon complete recov­

ery to an extreme level of performance. One

author’s (HSS) experience with determining

prognosis in working dogs has been compli­

cated by the fact that the dog whose perfor­

mance is greater than that of the standard pet

may not recover enough function to perform at

their original level. Will a spinal surgery absorb

the shock of a dog hitting the flyball box? Will

the dog be able to handle the turn? It is difficult

to assure a police officer that his canine partner

will be completely dependable when the offic­

er’s life is on the line.

Monitoring the changes in range of motion

(ROM) of experimentally produced surgical

injury to the cervical spines of mongrel dogs

produced interesting results (Panjabi et al.,

1988). A sham surgery that consisted of a skin

incision and reflecting of the paraspinal muscu­

lature and periosteum was compared with:

(1) Cutting of the supra‐ and infraspinous

ligaments at C4–C5

(2) C4 laminectomy

(3) C4 laminectomy and facetectomy.

spinal cord is very plausible because of lesion asym-

metry. The lack of spinal hyperesthesia would be con-

sistent since there are no nociceptive fibers in the

spinal cord tissue. Hansen type II intervertebral disc

protrusion is a common spinal cord disorder in older

dogs. Due to the progressive and insidious nature of a

disc protrusion, spinal hyperesthesia may or may not

be a clinical sign. Degenerative conditions, such as

degenerative myelopathy should also be considered a

differential in patients with progressive paraparesis. It

is important to perform thorough cross‐sectional

imaging of the spine to diagnose extradural compres-

sion or intramedullary disease. A presumptive diagno-

sis of degenerative myelopathy is based on ruling out

these causes of acquired myelopathy, which may be

treatable. Degenerative myelopathy can only be

definitively diagnosed based on microscopic exami-

nation of the spinal cord tissue.

Outcome: The DNA test for the SOD1 mutation was

homozygous (at risk) for the mutant allele. Since the

test result only reveals a risk factor, the client wanted

to rule out a treatable cause. A spinal MRI from T3 to

the sacrum was performed and revealed a mild disc

protrusion at the lumbosacral disc space. Since there

were no supportive clinical signs of degenerative

lumbosacral stenosis, the most likely presumptive

diagnosis was degenerative myelopathy.

The client opted to have the patient monitored

monthly by her veterinarian and pursued physical

rehabilitation including underwater treadmill ther-

apy, cavaletti, cone weaving, and ROM exercises. Six

months after diagnosis, patellar and flexor reflexes

became reduced. The patient also was becoming

more fatigued with exercises. It was opted to con-

tinue only with the underwater treadmill therapy and

focus on massage and passive ROM exercises.

The patient became nonambulatory paraparetic 10

months after diagnosis and muscle wasting was evi-

dent in the pelvic limbs. The patient developed uri-

nary incontinence. A cart to support the pelvic limbs

was recommended to enhance mobility. However,

the client felt her dog’s desire and attitude was dimin-

ishing and she opted for euthanasia.