Page 1172 - Small Animal Internal Medicine, 6th Edition

1144 PART IX Nervous System and Neuromuscular Disorders

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T9
T8

A B

L2

L3

C

FIG 65.14
(A) A 5-month-old Boxer puppy with back pain resulting from diskospondylitis. (B) and
(C) Lateral spinal radiographs reveal lesions at T8-T9 and L2-L3, with destruction of
adjacent vertebral body end plates, collapse of the intervertebral disk spaces, shortening
of the vertebral bodies, and new bone production around the ends of the affected
vertebral bodies.

cultures in some cases with negative blood and urine cul- effective. Quinolones can be added if gram-negative organ-
tures, but this is usually reserved for cases in which other isms are suspected. Ampicillin is the antibiotic of choice for
culture techniques have yielded negative results and the Actinomyces infections associated with grass awn migration.
response to an empirically selected antibiotic is inadequate. Antibiotics are administered parenterally for the first 3 to 5
A spinal needle is guided into the disk space and a small days whenever neurologic deficits are present, then oral
amount of sterile saline (0.3-0.5 mL) is injected and then administration is continued for at least 8 weeks and up to 6
aspirated for culture. Brucella serology or polymerase chain months if necessary.
reaction (PCR) should be considered in all affected dogs In addition to antibiotic therapy, the patient’s activity
because of the public health significance of brucellosis (see should be restricted to minimize discomfort and decrease
Chapter 55), despite its very low prevalence (<10%) in the the chance of pathologic fracture and luxation. Analge-
United States and Canada. sics may be administered for 3 to 5 days, but their use will
make it difficult to assess the efficacy of antibiotic therapy
Treatment and may make it more difficult to enforce strict cage rest.
Initial treatment of diskospondylitis consists of antibiotics, Most dogs show very rapid clinical improvement within the
cage rest, and analgesics. If an organism is isolated, suscep- first week of treatment. Dogs treated medically should be
tibility testing should guide antibiotic therapy. If an organ- reevaluated clinically and radiographically every 3 weeks.
ism is not found, initial treatment attempts should be With time, the lytic process should resolve and the affected
directed against Staphylococcus spp. Bactericidal antibiotics vertebrae should fuse. Antibiotics should be administered
with a spectrum against gram-positive organisms and the for a minimum of 8 weeks and may then be discontin-
ability to concentrate in bone are recommended. First- ued if the spine is no longer painful over the affected sites
generation cephalosporins (cefazolin, 25 mg/kg IV q8h; and there is no radiographically visible lysis. Most treated
cephalexin, 22 mg/kg PO q8h) and amoxicillin with clavu- animals do not relapse unless a foreign body causes the
lanate (Clavamox, 12.5-25 mg/kg PO q8h) have been diskospondylitis.