Spinal Epidural Empyema in Seven Dogs

Abstract

Objective-To characterize the clinical signs, diagnostic and surgical findings, and outcome in dogs with spinal epidural empyema (SEE). Study Design-Retrospective study. Animals-Seven dogs. Methods-Dogs with SEE between 1992 and 2001 were identified from a computerized medical record system. Inclusion criteria were: neurologic examination, vertebral column radiographs, myelography, antimicrobial culture and susceptibility of material collected surgically from the vertebral canal, a definitive diagnosis of SEE confirmed by surgery, and microscopic examination of tissue from the vertebral canal. Results-Common signs were lethargy, fever, anorexia, apparent spinal pain, and paraparesis/plegia. Common laboratory abnormalities were peripheral neutrophilia, and neutrophilic pleocytosis in cerebrospinal fluid (CSF). Three dogs had concurrent discospondylitis and 1 of these had vertebral luxation. On myelography, extradural spinal cord compression was focal (2 dogs), multifocal (3), or diffuse (2). Bacteria were isolated not from CSF but from blood, surgical site, pleural fluid, or urine in 6 dogs. Dogs were administered antibiotics and had surgical decompression by hemilaminectomy. Five dogs improved neurologically and had a good long-term outcome. Two dogs were euthanatized, 1 because of worsening of neurologic signs and pneumonia, and the other because of herniation of a cervical intervertebral disc 1 month postoperatively, unrelated to the SEE. Conclusion-Dogs with SEE may have a good outcome when treated by surgical decompression and antibiotic administration. Clinical Relevance-SEE should be included in a list of possible causes for dogs with fever, apparent spinal pain, and myelopathy. r

Medical management of spinal epidural empyema in five dogs

“…Clinical signs and clinicopathologic findings in these dogs were similar to those reported previously for dogs with spinal epidural empyema. 13,14,[20][21][22][23][24][25] Similarly, MRI findings were consistent with those previously reported for dogs with spinal epidural empyema, including hyperintense extradural lesions on T2-weighted images and contrast enhancement in a diffuse or ring-like pattern on T1-weighted images after IV administration of gadolinium-based contrast medium. 5,13,18,19 However, lesions on precontrast T1-weighted images varied from mildly hyperintense (dogs 1, 2, and 3) to hypointense (dogs 4 and 5).…”

“…The additional value of collecting CSF samples in dogs with spinal epidural empyema remains questionable, in that results of bacterial culture of CSF samples are often negative, 20 as was the case for the 3 dogs in the present report from which CSF samples were obtained. For these dogs, CSF samples were retrieved from sites cranial to the lesion to avoid needle placement within the infected lesion, which may have contributed to the negative results.…”

“…For instance, even though surgery provides direct access the lesion, in previous reports 13,14,20,21 of dogs with spinal epidural empyema, results of bacterial culture of samples obtained at the time of surgical debridement were positive for only 12. In human patients, positive results for bacterial culture of blood samples in conjunction with consistent clinical signs and MRI findings are considered diagnostic for spinal epidural empyema, 19 and organisms isolated from blood samples closely match those recovered from empyema fluid.…”

“…On the other hand, recovery time may be longer in human patients managed medically. 8 Other than a single conference abstract d describing 3 dogs with spinal epidural empyema that were successfully treated medically, all previous reports 13,17,20,21,23,24 of successful management of spinal epidural empyema in dogs involved surgical management. In human medicine, numerous reports 7-10 describe successful management with antimicrobials alone or in conjunction with percutaneous aspiration of septic fluid.…”

“…13,18-20,d In veterinary medicine, spinal epidural empyema is currently regarded as a surgical emergency, and results of surgical treatment have been reported previously. 14,[20][21][22][23][24][25] However, because a definitive diagnosis is more easily obtained with surgical management, there may be a reporting bias. For human patients, the choice of medical versus surgical management of spinal epidural empyema remains controversial.…”