Outcome of Conservative Management of Acute Thoracolumbar Disk Extrusion

In the Literature

Kahn S, Jeffery ND, Freeman P. Recovery of ambulation in small, nonbrachycephalic dogs after conservative management of acute thoracolumbar disk extrusion. J Vet Intern Med. 2024;38(5):2603-2611. doi:10.1111/jvim.17149

The Research …

Thoracolumbar myelopathy caused by acute intervertebral disk extrusion (IDE) is a common cause of presentation for dogs and typically involves both concussive and compressive injury to the spinal cord that may cause signs of back pain, paraparesis, paraplegia, loss of deep pain perception (DPP), loss of micturition, and other clinical signs.^1,2 Therapy consists of medical management and/or surgical management (typically, spinal cord decompression via hemilaminectomy).³ Surgery is generally believed to be more likely to result in a successful outcome in nonambulatory dogs with or without DPP³; however, a systematic review estimated that up to 86% of nonambulatory dogs with DPP can recover the ability to ambulate without surgery.⁴

This prospective study investigated the proportion of nonambulatory dogs with acute thoracolumbar IDE (n = 72) that recovered after 12 weeks of conservative management, time to recovery, and associated change in spinal cord compression. All dogs weighed <33.1 lb (15 kg) and were nonbrachycephalic; dachshunds were most common. An initial MRI confirmed the diagnosis in 67 dogs. All dogs received medical management (eg, pain medication, activity restriction/crate confinement, owner-provided rehabilitation, bladder management) in the home. Activity levels were gradually increased, and pain medications were gradually tapered and discontinued over the 12-week period. Recovery was defined as the ability to walk 10 consecutive steps unaided and without falling.

Of 51 dogs with DPP at presentation, 96% recovered ambulation in a median time of 11 days. Of 21 dogs without DPP at presentation, 48% recovered ambulation in a median time of 25 days. In 63 dogs that underwent a second MRI at the end of the study period, spinal cord compression was reduced; however, this finding was not correlated with recovery of ambulation, and its role in recovery of ambulation in medically managed dogs is unknown. Progressive ascending–descending myelomalacia was more frequent than in other studies,⁵ possibly due to inclusion of dogs with evidence of progressive ascending–descending myelomalacia at presentation that may have been excluded in previous reports.

… The Takeaways

Key pearls to put into practice:

• This study provides evidence that small, nonambulatory dogs with thoracolumbar IDE can recover ambulation within 12 weeks without surgery. In a previous study, dogs received spinal decompression surgery if medical management failed at 4 weeks⁶; some dogs may have recovered ambulation after 4 weeks if medical management had been continued.

• A minimum of 12 weeks of medical management should be considered in nonambulatory dogs with suspected or confirmed thoracolumbar IDE, as recovery of ambulation is likely, especially if DPP is intact. Managing expectations around length and potential of recovery may be particularly important when pet owners are unable or unwilling to accept referral.

• Conservative management may include analgesia, muscle relaxation, rehabilitation, activity restriction/crate confinement, nursing care (eg, bladder management), and other treatments.

• The primary care clinician, neurology specialist, and owner should work together. Support can be provided via phone calls, email, in-person examinations, and video-based evaluations.