Spinal osteomyelitis and epidural empyema in a dog due to migrating conifer material

Abstract

MIGRATION of foreign bodies to the lumbar spine has been reported in dogs but is uncommon (Johnston and Summers 1971, Brennan andIhrke 1983). When identified, the foreign body has invariably been a grass awn. Inhalation followed by migration via the pleural space, and ingestion and transabdominal migration, have been proposed as modes by which foreign material may reach the lumbar spine (Johnston and Summers 1971, Frendin and others 1999). This short communication describes a case of sudden-onset paraparesis due to a septic focus associated with the migration of a large sprig of conifer to the lumbar vertebral canal of a dog.A four-year-old female neutered dobermann was referred for evaluation of acute-onset non-ambulatory pelvic limb paresis. Patellar, panniculus and pelvic limb withdrawal reflexes were considered normal, as was pedal sensation. The thoracic limbs were neurologically normal. Bladder control at presentation was not determined. The dog was normothermic. The dog had a history of short episodes of intermittent lethargy and suspected back pain over two years, which had previously responded to antibiotic and anti-inflammatory drug treatment. The most recent episode had occurred 10 days before presentation, and had rapidly responded to medical treatment, with the owner reporting a return to normal within seven days.Radiographs of the thoracolumbar spine were obtained under general anaesthesia. There was profuse ventral spondylosis involving L2 and L3, an irregularly widened L2-L3 intervertebral disc space and variable radiopacity, including multiple punctate lucencies and sclerosis, of the involved vertebral bodies (Fig 1a). These findings were suggestive of persistent osteomyelitis of the vertebral bodies L2 and L3 and associated chronic discospondylitis. Lumbar myelography was performed by injection of 6 ml iohexol (Omnipaque; GE Healthcare) via lumbar puncture at L5-L6. There were multifocal mild deviations in the left and right contrast columns (on a ventrodorsal view) and a major deviation of the right contrast column towards the midline at the level of L2-L3 (Fig 1b).A right-sided hemilaminectomy centred over the L2-L3 intervertebral disc was performed. Perioperatively, 140 mg carprofen (Rimadyl; Pfizer) and 700 mg cefazolin (Kefzol; Lilly) were administered intravenously. Intravenous fluid therapy with lactated Ringer's solution (Aqupharm No11; Animalcare) was administered at a rate of 10 ml/kg/hour throughout the procedure. As the inner periosteum was incised, purulent fluid exuded from the epidural space. A layer of granulation tissue 2 to 3 mm thick covered the dural sac. The bone of the vertebral body of L2 was soft and contained a cavity 20 mm in diameter, which was explored with a small probe. A large sprig of plant material, approximately 25 mm in length (Fig 2), was retrieved from the defect. Tissue from the cavity was collected and submitted for histopathology and bacterial culture and sensitivity testing. The wound was closed routinely and the dog recovered from anaesthesia uneventful...

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).…”

“…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.…”

“…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.…”

Migrating sewing needle in the cervical vertebral canal in a dog

“…In three of these cases, acute neurological signs and pain were found (Platt and others 2007, Hicks and Bagley 2008, Smith and Fitzpatrick 2009) and while the third case developed clinical signs three years after microchip placement, it was suspected the implant had been placed within the C5-C6 interarcuate ligament and epaxial musculature, possibly in contact with the dorsal surface of the cranial left lamina of C6 (Joslyn and others 2010). Plant material that has migrated from different levels is a common migrating foreign body found in companion animals (Brennan and Ihrke 1983, Frendin and others 1999, Jones and Ober 2007, Schultz and Zwingenberger 2008, Sutton and others 2010, Potanas and others 2011, Whitty and others 2013). Although these foreign bodies can be difficult to observe due to their hypodense composition and usually small size, advanced imaging technique, such as CT or MRI, would allow direct visualisation of them or the secondary changes caused in the affected tissues (Frendin and others 1999, Young and others 2004, Jones and Ober 2007, Schultz and Zwingenberger 2008, Whitty and others 2013).…”

“…Clinical signs associated with foreign bodies in the vertebral canal can be caused by direct injury to the spinal cord by the foreign material, or related to haemorrhage, infection or granuloma formation secondary to the intruding material (Johnston and Summers 1971, Brockman and Trout 1991, Pratt and others 1999, Rayward 2002, Leskovar and others 2003, Dennis and others 2005, Granger and others 2007, Mateo and others 2007, Platt and others 2007, Hicks and Bagley 2008, Smith and Fitzpatrick 2009, Joslyn and others 2010, Schneider and others 2010, Sutton and others 2010, Potanas and others 2011, Tanaka and others 2012, Whitty and others 2013). Needles are very thin and of an inert material, so direct injury of the spinal cord should be theoretically minimal.…”