Page 853 - Clinical Small Animal Internal Medicine

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tumors include meningiomas, neuroepitheliomas, and vertebral endplates. Pathologic changes and lesion extent
VetBooks.ir nerve sheath tumors. Extradural tumors include primary can be more conspicuous with CT and MRI. Due to its
zoonotic potential, Brucella canis screening is indicated.
bone tumors, metastatic tumors, and hematopoietic
tumors (e.g., histiocytic disease, lymphoma, plasma cell
ity testing of bacteria isolated from urine or blood or
tumors). Tumors that involve the vertebral body cause Antimicrobial selection should be based on susceptibil-
secondary spinal cord compression. Metastatic disease from infected tissue.
of the spinal cord can occur from spread within the CNS
(drop metastasis) or from extraneural tissues via direct Trauma
extension or hematogenously. Hemangiosarcoma, mela-
nomas, and carcinomas are the most common tumors to Animals with spinal fractures and luxations are assessed
metastasize to the spinal cord and vertebral column. with minimal manipulation to prevent further injury and
displacement of the spine. Nociception is assessed in ple-
gic animals to assist with determining prognosis. Spinal
Inflammatory (Infectious, Noninfectious)
fracture/luxation in dogs and cats is most commonly asso-
Meningitis (inflammation of the meninges) and menin- ciated with severe external trauma and results in spinal
gomyelitis (inflammation of the meninges and spinal cord dysfunction. Diagnosis is based on radiography or
cord) cause focal or diffuse signs of myelopathy and cross‐sectional imaging of the entire spine. Nonsurgical or
severe spinal pain. Onset is acute, peracute or insidious. surgical management depends upon presence of instabil-
Signs typically progress but can wax and wane. ity. The prognosis for recovery from a spinal fracture/
Neurologic signs are variable and related to the area of luxation with loss of nociception is considered poor.
spinal cord affected. Common clinical signs include GP
ataxia, limb paresis, and paraspinal hyperesthesia. Lesion Vascular Occlusive Disorders
distribution can be focal or multifocal, causing asym-
metric neurologic deficits. Animals with meningomyeli- Fibrocartilaginous embolic myelopathy is the most com-
tis could also have signs of encephalitis. Spinal cord MRI mon cause of vascular occlusion of the spinal cord in dogs
combined with CSF analysis is the most reliable diagnos- and infrequently can occur in cats. FCE most commonly
tic approach for identifying the presence and extent of affects the younger, larger dog breeds but also occurs in
CNS inflammation. Some infectious agents affect other small dog breeds, with the miniature schnauzer overrep-
organ systems in addition to the CNS. Serology and resented. Onset of signs is often peracute or acute with
molecular techniques screen for infectious etiologies. little progression. Key neurologic signs include asymmet-
Disease confirmation often requires biopsy or necropsy ric paresis with lack of paraspinal hyperesthesia.
examination. Localization frequently reflects the segments of the cervi-
Common infectious diseases causing myelopathy cothoracic and lumbosacral intumescences; however, seg-
include viral (e.g., feline coronavirus, feline infectious ments within L4–S3 and T3–L3 are most commonly
peritonitis, canine distemper virus, feline immunodefi- reported. The pathogenesis still remains enigmatic. Spinal
ciency virus, feline leukemia virus), protozoal, rickettsial, cord arteries become occluded with fibrocartilage that
algal, and fungal diseases. In the dog, canine distemper originates from the nucleus pulposus of the intervertebral
virus and protozoa are the most frequently identified disc. The clinical presentation is sometimes difficult to
agents. Infectious meningomyelitis seems to be the most distinguish from the concussive, noncompressive extru-
common cause underlying myelopathy in the cat. sions of the intervertebral disc. Prognosis is dependent on
Granulomatous meningoencephalomyelitis (GME) and the severity of neurologic deficits, lesion location and
steroid‐responsive meningitis‐arteritis are noninfectious extent, and owner’s commitment to nursing care. The
inflammatory diseases that predominate in the dog. prognosis is favorable in patients that show improvement
Inflammation/infections of the vertebral column can within two weeks of onset.
involve the vertebra (osteomyelitis, physitis) or interver- In cats with acute onset of asymmetric paresis/
tebral disc space (discospondylitis). Spinal cord epidural paralysis, aortic thrombosis is a primary differential.
empyema is defined as an extensive accumulation of The pelvic limbs are commonly affected, with signs of
purulent material in the epidural space of the vertebral loss of femoral pulse, pain and firmness in the mus-
column related to direct extension of osteomyelitis or cles, and loss of nociception distally. Hypertrophic
discospondylitis. Discospondylitis is associated with cardiomyopathy is the most frequent underlying dis-
bacterial or fungal infection of the intervertebral disc ease. Diagnosis is suspected based upon clinical signs,
and contiguous vertebrae. Hyperesthesia of the vertebral elevated creatine kinase concentration, and evidence
column is the primary clinical sign. Radiographic fea- of cardiac disease. Initial therapy involves manage-
tures of discospondylitis include lysis and sclerosis of the ment of the cardiac disease, preventing further clot