Hemilaminectomy for thoracolumbar Hansen Type I intervertebral disk disease in ambulatory dogs with or without neurologic deficits: 39 cases (2008–2010)

Objective To describe prognostic factors, outcome, and time to recovery among ambulatory dogs having hemilaminectomy for Hansen Type I intervertebral disk disease. Study Design Retrospective case series. Animals Dogs (n = 38; 39 hemilaminectomies). Methods Medical records (January 2008–May 2010) on all dogs that had hemilaminectomy for Hansen Type I intervertebral disk disease were reviewed. Records for dogs that were ambulatory preoperatively were analyzed for signalment, duration and severity of signs, presence of neurologic deficits, and postoperative outcome. Dogs were categorized based on Frankel score and subcategorized by their level of conscious proprioceptive (CP) deficit. Postoperatively, time to ambulation and to regain normal CP responses was recorded. Results for each group were compared using a χ 2 test and considered significant when P  < .05. Recovery times were analyzed using a Cox proportional hazards model. Results Seven dogs were categorized as modified Frankel grade I preoperatively and 32 dogs as grade II with varying levels of deficits (1 of these dogs had previously been operated as grade II and was reoperated again as grade II). Increasing degree of CP deficit preoperatively was significantly correlated with longer time to ambulation ( P  = .005) as well as longer time to CP normal ( P  = .01). Duration of signs was not significantly correlated with time to ambulation or neurologic recovery for either grade I or II dogs. Conclusions Most dogs recovered well with surgical decompression. Increasing degree of deficits preoperatively is significantly correlated with longer recovery time.