Prognosis in Dogs with Caudal Lumbar Intervertebral Disk Extrusions
Wanda J. Gordon-Evans, DVM, PhD, DACVS, DACVSMR, University of Minnesota
In the literature
Pfund R, Forward AK, Fentem R, Nagendran A, Fraser AR, Crawford AH. Postoperative outcome of ambulatory dogs with intervertebral disc extrusion causing incontinence and/or tail dysfunction: 18 cases (2010-2020). J Small Anim Pract. 2022;63(7):550-558. doi:10.1111/jsap.13497
The Research …
Intervertebral disk disease (IVDD) is common in dogs and can result in back pain, muscle weakness, and sensory deficits. An intervertebral disk is composed of a gelatinous nucleus pulposus surrounded by the annulus fibrosis. IVDD occurs when the nucleus pulposus degenerates and extrudes out of the annulus fibrosis and into the spinal canal. Extrusion location, contusive force of the extrusion, and compression of the spinal cord and/or nerve roots can cause clinical signs. The spinal cord in the caudal lumbar area terminates into the cauda equina, a group of nerves that may have higher capacity for repair.1-4
This study retrospectively evaluated 18 dogs with IVDD in the caudal lumbar area (L4-S1) with urinary incontinence, fecal incontinence, and/or tail paresis or paralysis to determine the functional outcome of surgical treatment, as well as possible factors affecting outcome.
Cavalier King Charles spaniels and cocker spaniels were overrepresented in the study population. Fifty percent of dogs had extrusions at L5-L6. Duration of clinical signs before presentation ranged from 2 to 60 days. Median initial follow-up time was 30 days, at which time 86% of dogs with urinary incontinence, 90% of dogs with fecal incontinence, and 87% of dogs with tail paresis or paralysis had regained full function. Dogs that did not fully recover had longer duration (≈28 days) of and more severe clinical signs (eg, combination of fecal and urinary incontinence with tail paresis) prior to presentation.
Although this study was small and retrospective, it provides evidence for a good prognosis in patients with caudal lumbar IVDD.
… The Takeaways
Key pearls to put into practice:
1. Dogs with caudal spinal IVDD and associated signs can recover full function of urinary and fecal continence with surgical intervention. 2. Cavalier King Charles spaniels and cocker spaniels may be more commonly affected by IVDD in the caudal lumbar region than other breeds. 3. Duration and severity of clinical signs prior to treatment can be prognostic indicators.